import numpy as np for access to np.sqrt() on line 17

[cclauss]

flake8 testing of https://github.com/hzwer/LearningToPaint on Python 3.7.1

$ flake8 . --count --select=E9,F63,F72,F82 --show-source --statistics

./baseline/DRL/actor.py:15:9: F821 undefined name 'init'
        init.xavier_uniform(m.weight, gain=np.sqrt(2))
        ^
./baseline/DRL/actor.py:15:44: F821 undefined name 'np'
        init.xavier_uniform(m.weight, gain=np.sqrt(2))
                                           ^
./baseline/DRL/actor.py:16:9: F821 undefined name 'init'
        init.constant(m.bias, 0)
        ^
3     F821 undefined name 'init'
3

E901,E999,F821,F822,F823 are the "showstopper" flake8 issues that can halt the runtime with a SyntaxError, NameError, etc. These 5 are different from most other flake8 issues which are merely "style violations" -- useful for readability but they do not effect runtime safety.

• F821: undefined name name
• F822: undefined name name in __all__
• F823: local variable name referenced before assignment
• E901: SyntaxError or IndentationError
• E999: SyntaxError -- failed to compile a file into an Abstract Syntax Tree