![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |
System Dependencies
Dependant Packages
Launch files
Messages
Services
Plugins
Recent questions tagged launch_frontend_py at Robotics Stack Exchange
![]() |
launch_frontend_py package from launch_frontend_py repolaunch_frontend_py |
ROS Distro
|
Package Summary
Version | 0.0.0 |
License | Apache License 2.0 |
Build type | AMENT_CMAKE |
Use | RECOMMENDED |
Repository Summary
Checkout URI | https://github.com/ros-tooling/launch_frontend_py.git |
VCS Type | git |
VCS Version | main |
Last Updated | 2025-10-01 |
Dev Status | DEVELOPED |
Released | UNRELEASED |
Contributing |
Help Wanted (-)
Good First Issues (-) Pull Requests to Review (-) |
Package Description
Maintainers
- Emerson Knapp
Authors
- Emerson Knapp
Python frontend for ROS 2 Launch
The package launch
is the implementation, the “plumbing” of the ROS 2 launch system.
XML and YAML on the other hand are frontends to launch.
That is, they are the intended user-facing API.
However, much of the community got hooked on Python launchfiles due to early adoption when the frontends were incomplete.
With that in mind, and the extensive explicit use of exact filenames and PythonLaunchDescriptionSource
, migration to these frontends is difficult for packages with downstream consumers.
Enter launch_frontend_py
- this package provides a Python-language frontend to launch
, with identical usage to the XML and YAML versions.
It provides the same benefits of conciseness, declarative style, while allowing launchfiles to stay in Python.
Usage
The available actions and substitutions are identical to XML and YAML launchfiles, with one caveat:
[!NOTE] Some launch Actions and their attributes use reserved Python keywords, the known cases are
for
Action andif
attribute for conditions. For all cases, an underscore_
is added at the end:for_
,if_
.
Here is an example launchfile with a few features:
from launch_frontend_py import launch
from launch_frontend_py.actions import arg, executable
def generate_launch_description():
return launch([
arg(name='message', default='hello world'),
arg(name='condition', default='True'),
executable(cmd='echo $(var message)', output='both'),
executable(cmd='echo hello conditional', if_='$(var condition)', output='both'),
executable(cmd='echo hello not-condition', if_='$(not $(var condition))', output='both'),
])
Package Dependencies
Deps | Name |
---|---|
ament_cmake | |
ament_cmake_python | |
ament_copyright | |
ament_lint_auto | |
ament_lint_common | |
ament_cmake_mypy | |
ament_cmake_pytest | |
launch |