How to make PyCharm always show line numbers
PyCharm Version 3.4.1(For all files in the project):
File -> Preferences -> Editor (IDE Settings) -> Appearance -> mark 'Show line numbers'
PyCharm Version 3.4.1(only for existing file in the project):
View -> Active Editor -> Show Line Numbers
For version 4.0, 4.5 on Windows
File -> Settings
Then,
Editor -> General -> Appearance -> Show line numbers
For version 4.0 on Mac OSX
PyCharm-->Preferences
Then,
Editor-->General-->Appearance-->checkbox: "Show line numbers"
For version 3.0 (Community Edition):
File -> Settings -> Editor (under IDE Settings) -> Appearance -> check 'Show line numbers'
Version 2.6 and above:
PyCharm (far left menu) -> Preferences... -> Editor (bottom left section) -> General -> Appearance -> Show line numbers checkbox
Version 2.5 and below:
Settings -> Editor -> General -> Appearance -> Show line numbers checkbox