How to evaluate PEP-508-style platform markers?
up vote
2
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I'd like to programmatically evaluate PEP-508-style platform markers such as platform_system == 'Windows'. It's not terribly challenging to implement a parser, but I assume there is one in pip. What is it called and how can I import & use it in my own script?
python pip
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
add a comment |
up vote
2
down vote
favorite
I'd like to programmatically evaluate PEP-508-style platform markers such as platform_system == 'Windows'. It's not terribly challenging to implement a parser, but I assume there is one in pip. What is it called and how can I import & use it in my own script?
python pip
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
pip does not have a public library API, and the pip devs don't want people importing & using the code in their own scripts. See the documentation for more information.
– jwodder
Nov 21 at 17:58
Thanks for the heads-up. I kinda remembered that and since I'm controlling the whole environment, I'm fine with ignoring that.
– Tamás Szelei
Nov 21 at 18:08
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
I'd like to programmatically evaluate PEP-508-style platform markers such as platform_system == 'Windows'. It's not terribly challenging to implement a parser, but I assume there is one in pip. What is it called and how can I import & use it in my own script?
python pip
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
I'd like to programmatically evaluate PEP-508-style platform markers such as platform_system == 'Windows'. It's not terribly challenging to implement a parser, but I assume there is one in pip. What is it called and how can I import & use it in my own script?
python pip
python pip
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
asked Nov 21 at 17:54
Tamás Szelei
13.9k1377146
13.9k1377146
pip does not have a public library API, and the pip devs don't want people importing & using the code in their own scripts. See the documentation for more information.
– jwodder
Nov 21 at 17:58
Thanks for the heads-up. I kinda remembered that and since I'm controlling the whole environment, I'm fine with ignoring that.
– Tamás Szelei
Nov 21 at 18:08
add a comment |
pip does not have a public library API, and the pip devs don't want people importing & using the code in their own scripts. See the documentation for more information.
– jwodder
Nov 21 at 17:58
Thanks for the heads-up. I kinda remembered that and since I'm controlling the whole environment, I'm fine with ignoring that.
– Tamás Szelei
Nov 21 at 18:08
pip does not have a public library API, and the pip devs don't want people importing & using the code in their own scripts. See the documentation for more information.
– jwodder
Nov 21 at 17:58
pip does not have a public library API, and the pip devs don't want people importing & using the code in their own scripts. See the documentation for more information.
– jwodder
Nov 21 at 17:58
Thanks for the heads-up. I kinda remembered that and since I'm controlling the whole environment, I'm fine with ignoring that.
– Tamás Szelei
Nov 21 at 18:08
Thanks for the heads-up. I kinda remembered that and since I'm controlling the whole environment, I'm fine with ignoring that.
– Tamás Szelei
Nov 21 at 18:08
add a comment |
1 Answer
1
active
oldest
votes
up vote
2
down vote
accepted
pkg_resources
pkg_resources (part of the setuptools package) provides marker evaluation function.
In [1]: from pkg_resources import evaluate_marker
In [2]: evaluate_marker('sys_platform == "darwin"')
Out[2]: True
In [3]: evaluate_marker('python_version > "3.7"')
Out[3]: False
In [4]: evaluate_marker('implementation_name == "cpython"')
Out[4]: True
In [5]: evaluate_marker('garbage')
Traceback (most recent call last):
File "/Users/hoefling/Library/Python/3.7/lib/python/site-packages/IPython/core/interactiveshell.py", line 2961, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-2-69434540d2ec>", line 1, in <module>
evaluate_marker('garbage')
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1372, in evaluate_marker
raise SyntaxError(e)
File "<string>", line unknown
SyntaxError: Invalid marker: 'garbage', parse error at 'garbage'
etc.
packaging
Under the hood, pkg_resources.evaluate_marker uses packaging.markers.Marker.evaluate from the packaging package, so you can use that instead:
In [6]: from packaging.markers import Marker
In [7]: Marker('"linux" in sys_platform').evaluate()
Out[7]: False
answered Nov 22 at 2:39
hoefling
11.2k42759
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Glad I could help!
– hoefling
Nov 22 at 12:27
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
2
down vote
accepted
pkg_resources
pkg_resources (part of the setuptools package) provides marker evaluation function.
In [1]: from pkg_resources import evaluate_marker
In [2]: evaluate_marker('sys_platform == "darwin"')
Out[2]: True
In [3]: evaluate_marker('python_version > "3.7"')
Out[3]: False
In [4]: evaluate_marker('implementation_name == "cpython"')
Out[4]: True
In [5]: evaluate_marker('garbage')
Traceback (most recent call last):
File "/Users/hoefling/Library/Python/3.7/lib/python/site-packages/IPython/core/interactiveshell.py", line 2961, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-2-69434540d2ec>", line 1, in <module>
evaluate_marker('garbage')
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1372, in evaluate_marker
raise SyntaxError(e)
File "<string>", line unknown
SyntaxError: Invalid marker: 'garbage', parse error at 'garbage'
etc.
packaging
Under the hood, pkg_resources.evaluate_marker uses packaging.markers.Marker.evaluate from the packaging package, so you can use that instead:
In [6]: from packaging.markers import Marker
In [7]: Marker('"linux" in sys_platform').evaluate()
Out[7]: False
answered Nov 22 at 2:39
hoefling
11.2k42759
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Glad I could help!
– hoefling
Nov 22 at 12:27
add a comment |
up vote
2
down vote
accepted
pkg_resources
pkg_resources (part of the setuptools package) provides marker evaluation function.
In [1]: from pkg_resources import evaluate_marker
In [2]: evaluate_marker('sys_platform == "darwin"')
Out[2]: True
In [3]: evaluate_marker('python_version > "3.7"')
Out[3]: False
In [4]: evaluate_marker('implementation_name == "cpython"')
Out[4]: True
In [5]: evaluate_marker('garbage')
Traceback (most recent call last):
File "/Users/hoefling/Library/Python/3.7/lib/python/site-packages/IPython/core/interactiveshell.py", line 2961, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-2-69434540d2ec>", line 1, in <module>
evaluate_marker('garbage')
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1372, in evaluate_marker
raise SyntaxError(e)
File "<string>", line unknown
SyntaxError: Invalid marker: 'garbage', parse error at 'garbage'
etc.
packaging
Under the hood, pkg_resources.evaluate_marker uses packaging.markers.Marker.evaluate from the packaging package, so you can use that instead:
In [6]: from packaging.markers import Marker
In [7]: Marker('"linux" in sys_platform').evaluate()
Out[7]: False
answered Nov 22 at 2:39
hoefling
11.2k42759
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Glad I could help!
– hoefling
Nov 22 at 12:27
add a comment |
up vote
2
down vote
accepted
up vote
2
down vote
accepted
pkg_resources
pkg_resources (part of the setuptools package) provides marker evaluation function.
In [1]: from pkg_resources import evaluate_marker
In [2]: evaluate_marker('sys_platform == "darwin"')
Out[2]: True
In [3]: evaluate_marker('python_version > "3.7"')
Out[3]: False
In [4]: evaluate_marker('implementation_name == "cpython"')
Out[4]: True
In [5]: evaluate_marker('garbage')
Traceback (most recent call last):
File "/Users/hoefling/Library/Python/3.7/lib/python/site-packages/IPython/core/interactiveshell.py", line 2961, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-2-69434540d2ec>", line 1, in <module>
evaluate_marker('garbage')
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1372, in evaluate_marker
raise SyntaxError(e)
File "<string>", line unknown
SyntaxError: Invalid marker: 'garbage', parse error at 'garbage'
etc.
packaging
Under the hood, pkg_resources.evaluate_marker uses packaging.markers.Marker.evaluate from the packaging package, so you can use that instead:
In [6]: from packaging.markers import Marker
In [7]: Marker('"linux" in sys_platform').evaluate()
Out[7]: False
answered Nov 22 at 2:39
hoefling
11.2k42759
pkg_resources
pkg_resources (part of the setuptools package) provides marker evaluation function.
In [1]: from pkg_resources import evaluate_marker
In [2]: evaluate_marker('sys_platform == "darwin"')
Out[2]: True
In [3]: evaluate_marker('python_version > "3.7"')
Out[3]: False
In [4]: evaluate_marker('implementation_name == "cpython"')
Out[4]: True
In [5]: evaluate_marker('garbage')
Traceback (most recent call last):
File "/Users/hoefling/Library/Python/3.7/lib/python/site-packages/IPython/core/interactiveshell.py", line 2961, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-2-69434540d2ec>", line 1, in <module>
evaluate_marker('garbage')
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/pkg_resources/__init__.py", line 1372, in evaluate_marker
raise SyntaxError(e)
File "<string>", line unknown
SyntaxError: Invalid marker: 'garbage', parse error at 'garbage'
etc.
packaging
Under the hood, pkg_resources.evaluate_marker uses packaging.markers.Marker.evaluate from the packaging package, so you can use that instead:
In [6]: from packaging.markers import Marker
In [7]: Marker('"linux" in sys_platform').evaluate()
Out[7]: False
answered Nov 22 at 2:39
hoefling
11.2k42759
edited Nov 22 at 2:46
answered Nov 22 at 2:39
hoefling
11.2k42759
answered Nov 22 at 2:39
hoefling
11.2k42759
answered Nov 22 at 2:39
hoefling
11.2k42759
11.2k42759
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Glad I could help!
– hoefling
Nov 22 at 12:27
add a comment |
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Glad I could help!
– hoefling
Nov 22 at 12:27
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Perfect, thank you very much! This is exactly what I needed.
– Tamás Szelei
Nov 22 at 10:31
Glad I could help!
– hoefling
Nov 22 at 12:27
Glad I could help!
– hoefling
Nov 22 at 12:27
add a comment |
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pip does not have a public library API, and the pip devs don't want people importing & using the code in their own scripts. See the documentation for more information.
– jwodder
Nov 21 at 17:58
Thanks for the heads-up. I kinda remembered that and since I'm controlling the whole environment, I'm fine with ignoring that.
– Tamás Szelei
Nov 21 at 18:08