Spaces in Python coding style

问题:

Python tutorial says "Use spaces around operators and after commas, but not directly inside bracketing constructs: a = f(1, 2) + g(3, 4)." What does "not directly inside bracketing constructs" exactly mean?

回答1:

That probably comes from PEP 8 -- Style Guide for Python Code. Specifically, see the section on "Whitespace in Expressions and Statements."

From that section:

Avoid extraneous whitespace in the following situations:

- Immediately inside parentheses, brackets or braces.

  Yes: spam(ham[1], {eggs: 2})
  No:  spam( ham[ 1 ], { eggs: 2 } )

回答2:

It means you shouldn't do things like a = f ( 1 ) or l = [ 2, 3 ].

回答3:

I think it means do this:

x = (1, 2)

not this:

x = ( 1, 2 )