Replace a platform.system() check with sys.platform #51766
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Summary: Check if we are on Windows using `sys.platform` rather than `platform.system()`. Even though `platform.system()` is more modern, it has a few downsides: this performs a runtime check of the platform type, which has non-zero overhead. On Linux it actually executes the separate `/bin/uname` process. On the other hand `sys.platform` is determined when the Python interpreter is compiled, so this is a simple hard-coded string. Because it is a runtime check, `platform.system()` checks also cannot be analyzed by static type checkers like Pyre and Mypy. These type checkers do understand `sys.platform` checks, and can correctly avoid complaining about code paths that use platform-specific modules and functions. e.g., they can avoid complaining about `ctypes.WinDLL` not existing on Linux if its use is guarded by a `sys.platform` check. Test Plan: Ran tests on Linux, and will check CI test results. [ghstack-poisoned]
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This was referenced Feb 5, 2021
Summary: Check if we are on Windows using `sys.platform` rather than `platform.system()`. Even though `platform.system()` is more modern, it has a few downsides: this performs a runtime check of the platform type, which has non-zero overhead. On Linux it actually executes the separate `/bin/uname` process. On the other hand `sys.platform` is determined when the Python interpreter is compiled, so this is a simple hard-coded string. Because it is a runtime check, `platform.system()` checks also cannot be analyzed by static type checkers like Pyre and Mypy. These type checkers do understand `sys.platform` checks, and can correctly avoid complaining about code paths that use platform-specific modules and functions. e.g., they can avoid complaining about `ctypes.WinDLL` not existing on Linux if its use is guarded by a `sys.platform` check. Test Plan: Ran tests on Linux, and will check CI test results. Differential Revision: [D26271724](https://our.internmc.facebook.com/intern/diff/D26271724) [ghstack-poisoned]
Summary: Check if we are on Windows using `sys.platform` rather than `platform.system()`. Even though `platform.system()` is more modern, it has a few downsides: this performs a runtime check of the platform type, which has non-zero overhead. On Linux it actually executes the separate `/bin/uname` process. On the other hand `sys.platform` is determined when the Python interpreter is compiled, so this is a simple hard-coded string. Because it is a runtime check, `platform.system()` checks also cannot be analyzed by static type checkers like Pyre and Mypy. These type checkers do understand `sys.platform` checks, and can correctly avoid complaining about code paths that use platform-specific modules and functions. e.g., they can avoid complaining about `ctypes.WinDLL` not existing on Linux if its use is guarded by a `sys.platform` check. Test Plan: Ran tests on Linux, and will check CI test results. Differential Revision: [D26271724](https://our.internmc.facebook.com/intern/diff/D26271724) [ghstack-poisoned]
xsacha
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Mar 31, 2021
Summary: Pull Request resolved: pytorch#51766 Check if we are on Windows using `sys.platform` rather than `platform.system()`. Even though `platform.system()` is more modern, it has a few downsides: this performs a runtime check of the platform type, which has non-zero overhead. On Linux it actually executes the separate `/bin/uname` process. On the other hand `sys.platform` is determined when the Python interpreter is compiled, so this is a simple hard-coded string. Because it is a runtime check, `platform.system()` checks also cannot be analyzed by static type checkers like Pyre and Mypy. These type checkers do understand `sys.platform` checks, and can correctly avoid complaining about code paths that use platform-specific modules and functions. e.g., they can avoid complaining about `ctypes.WinDLL` not existing on Linux if its use is guarded by a `sys.platform` check. ghstack-source-id: 121107705 Test Plan: Ran tests on Linux, and will check CI test results. Reviewed By: mraway Differential Revision: D26271724 Pulled By: simpkins fbshipit-source-id: b86e427e4ceec0324464ba4bc88b95d5813172d0
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Stack from ghstack:
Summary:
Check if we are on Windows using
sys.platformrather thanplatform.system(). Even thoughplatform.system()is more modern, ithas a few downsides: this performs a runtime check of the platform type,
which has non-zero overhead. On Linux it actually executes the separate
/bin/unameprocess. On the other handsys.platformis determinedwhen the Python interpreter is compiled, so this is a simple hard-coded
string.
Because it is a runtime check,
platform.system()checks also cannot beanalyzed by static type checkers like Pyre and Mypy. These type
checkers do understand
sys.platformchecks, and can correctly avoidcomplaining about code paths that use platform-specific modules and
functions. e.g., they can avoid complaining about
ctypes.WinDLLnotexisting on Linux if its use is guarded by a
sys.platformcheck.Test Plan:
Ran tests on Linux, and will check CI test results.
Differential Revision: D26271724