Rules

1. Blank lines
   • Surround top-level function and class definitions with two blank lines.
   • Method definitions inside a class are surrounded by a single blank line.
   • Blank line doesn't contains whitespace
2. Input a whitespace after ', input a whitespace after ':'
3. Line too long (131 > 79 characters)
   • Limit all lines to a maximum of 79 characters
   • Limiting the required editor window width makes it possible to have several files open side-by-side, and works well when using code review tools that present the two versions in adjacent columns.
4. Continuation lines should align wrapped elements either vertically using Python's implicit line joining inside parentheses, brackets and braces, or using a handing indent. When using a hanging indent the following shoudl be considered; there should be no arguments on the first line and further indentation should be used to clearly distinguish itself as a continuation line:

# Correct:
# Aligned with opening delimiter.
foo = long_function_name(var_one, var_two,
                         var_three, var_four)

# Add 4 spaces (an extra level of indentation) to distinguish arguments from the rest.
def long_function_name(
        var_one, var_two, var_three,
        var_four):
    print(var_one)

# Hanging indents should add a level.
foo = long_function_name(
    var_one, var_two,
    var_three, var_four)

# Wrong:
# Arguments on first line forbidden when not using vertical alignment.
foo = long_function_name(var_one, var_two,
    var_three, var_four)

# Further indentation required as indentation is not distinguishable.
def long_function_name(
    var_one, var_two, var_three,
    var_four):
    print(var_one)

5. Imports should usually be on separate lines:

# Correct:
import os
import sys

# Wrong:
import sys, os
It's okay to say this though:

# Correct:
from subprocess import Popen, PIPE

6. Imports should be grouped in the following order:
   • Standard library imports.
   • Related third party imports.
   • Local application/library specific imports.
   • You should put a blank line between each group of imports.
7. Whitespace in Expressions and Statements
   If operators with different priorities are used, consider adding whitespace around the operators with the lowest priority(ies). Use your own
   judgment; however, never use more than one space, and always have the same amount of whitespace on both sides of a binary operator:

# Correct:
i = i + 1
submitted += 1
x = x*2 - 1
hypot2 = x*x + y*y
c = (a+b) * (a-b)

# Wrong:
i=i+1
submitted +=1
x = x * 2 - 1
hypot2 = x * x + y * y
c = (a + b) * (a - b) 

8. Don't use spaces around the = sign when used to indicate a keyword argument, or when used to indicate a default value for an
   unannotated function parameter:

# Correct:
def complex(real, imag=0.0):
    return magic(r=real, i=imag)

# Wrong:
def complex(real, imag = 0.0):
    return magic(r = real, i = imag) 

9. Check if vaiable equals a constant
   • You don't need to explicity compare a value to True, or None, or 0, you can just add it to the if statement.

# Bad:
if attr == True:
    print 'True!'

if attr == None:
    print 'attr is None!'

# Good:
# Just check the value
if attr:
    print 'attr is truthy!'

# or check for the opposite
if not attr:
    print 'attr is falsey!'

# or, since None is considered false, explicitly check for it
if attr is None:
    print 'attr is None!'

10. Comments that contradict the code are worse than no comments. Always make a priority of keeping the
    comments up-to-date when the code changes!
    Comments should be complete sentences. The first word should be capitalized, unless it is an identifier that begins with a lower case letter
    (never alter the case of identifiers!)
11. Python rules:
    • Classes are PascalCase
    • CONSTANTS are UPPER_CASE
    • Variables are snake_case
    • methods are snake_case
12. SQLAlchemy
    • xxx.is_(None) instead of xxx == None,
    • xxx.isnot_(None) instead of xxx != None

Restful API