bytes == str

[Skaperen]

bytes == str is always True on python2 and always False on python3.  so i have been using it for version testing, at least for major version numbers.  one problem is that it is obscure code; the meaning isn't obvious just looking at that alone.

[Larz60+]

you can use sys.version_info

Output:
Python 3.6:

sys.version_info
    A tuple containing the five components of the version number: major, minor, micro, releaselevel, and serial. All values except releaselevel are integers; the release level is 'alpha', 'beta', 'candidate', or 'final'. The version_info value corresponding to the Python version 2.0 is (2, 0, 0, 'final', 0). The components can also be accessed by name, so sys.version_info[0] is equivalent to sys.version_info.major and so on.
    Changed in version 3.1: Added named component attributes.

Python 2.7:


sys.version_info

    A tuple containing the five components of the version number: major, minor, micro, releaselevel, and serial. All values except releaselevel are integers; the release level is 'alpha', 'beta', 'candidate', or 'final'. The version_info value corresponding to the Python version 2.0 is (2, 0, 0, 'final', 0). The components can also be accessed by name, so sys.version_info[0] is equivalent to sys.version_info.major and so on.

    New in version 2.0.

    Changed in version 2.7: Added named component attributes

[Skaperen]

yes i had used if sys.version_info.major < 3: but if bytes == str: seemed to not need to import anything.  i could do the version test to decide which of two big import statements to use.

[wavic]

You can import just the version_info if you don't want all the sys module. After all, it is part of Python so the import statement is not such a big deal.

[Skaperen]

i was thinking more in terms of doing the test before importing anything.