flake8-multiline-function-call-equals 0.1.4

A package that checks to ensure spaces around `=` in multiline function calls

flake8-multiline-function-call-equals

A (higly opinonated) flake8 extension that checks for spaces around = in multiline function calls

Motivation

For improved readability, function calls that span multiple physical lines should have a single space on either side of the = when using named arguments. Additionally, each physical line may hve exatly one argument (named, or otherwise).

By contrast, there should be no spaces around the =, when a function with named arguments is called on one physical line (i.e. not a multiline function call)

Examples

EQA100

foo(a = 5, b = 2)

This is a single line function call with named arguments. In this case, there should be no spaces around the = when passing values to the named arguments. The correct call would be

foo(a=5, b=2)

EQA101

foo(a  = 5,  # incorrect
    b = 2,  # correct
    )

This is a multiline function call with named arguments. In this case, there should be a single space on each side of the = when passing values to the named arguments. The correct call would be

foo(a = 5,
    b = 2,
    )

EQA102

foo(a= 5,  # incorrect - no space on the left
    b = 2,  # correct
    )

foo(a=5,  # incorrect - no spaces at all
    b = 2,  # correct
    )

These are multiline function calls with named arguments. In these cases, there should be a single space on each side of the = when passing values to the named arguments. The correct call would be

foo(a = 5,
    b = 2,
    )

EQA103

foo(a = 5,
           # incorrect - there should be no empty line here
    b = 2,
    )

foo(a = 5,
    b = 2,
           # incorrect - there should be no empty line here
    )

These are multiline function calls with named arguments. In these cases, there should be no empty lines within the function call. The correct call would be

foo(a = 5,
    b = 2,
    )

EQA104

foo(a = 5, b = 2,  # incorrect - only one argument per line
    )

foo(3, 4,  # incorrect - only one argument per line
    a = 5,
    b = 2,
    )

These are multiline function calls. In these cases, only one argument may be listed per line. The correct calls would be

foo(a = 5,
    b = 2,  # incorrect - only one argument per line
    )

foo(3,
    4,  # incorrect - only one argument per line
    a = 5,
    b = 2,
    )

EQA105

foo(  # incorrect - the first argument should be on this line
    a = 5,
    b = 2,
    )

This is a multiline function call. In this case, the first argument should be on the line with the open paren. The correct call would be

foo(a = 5,
    b = 2,
    )

EQA106

foo(a = 5,
    b = 2,)  # incorrect - closing paren should be on a separate line

This is a multiline function call. In this case, the closing parenthesis should be on its own line. The correct call would be

foo(a = 5,
    b = 2,
    )

List of Error Codes

Code	Description
EQA100	Too many whitespaces surrounding assignment operator in single-line function call
EQA101	Too many whitespaces surrounding assignment operator in multiline function call
EQA102	Too few whitespaces surrounding assignment operator in multiline function call
EQA103	Empty line in multiline function call
EQA104	Multiple arguments on the same line in multiline function call
EQA105	First argument does not start on the call line in multiline function call
EQA106	Closing paren is on the same line as the last argument

Limitations

Python's AST parser does not mention the position of the = in argument passing. Consequently, the following code block will pass linting, even though it violates the spirit of the rule this linter attempts to enforce

foo(a=  5,  # this will incorrectly pass the lint check
    b = 2,
    )