in pylib/pycodestyle/pycodestyle.py [0:0]
def missing_whitespace_around_operator(logical_line, tokens):
r"""Surround operators with a single space on either side.
- Always surround these binary operators with a single space on
either side: assignment (=), augmented assignment (+=, -= etc.),
comparisons (==, <, >, !=, <=, >=, in, not in, is, is not),
Booleans (and, or, not).
- If operators with different priorities are used, consider adding
whitespace around the operators with the lowest priorities.
Okay: i = i + 1
Okay: submitted += 1
Okay: x = x * 2 - 1
Okay: hypot2 = x * x + y * y
Okay: c = (a + b) * (a - b)
Okay: foo(bar, key='word', *args, **kwargs)
Okay: alpha[:-i]
E225: i=i+1
E225: submitted +=1
E225: x = x /2 - 1
E225: z = x **y
E226: c = (a+b) * (a-b)
E226: hypot2 = x*x + y*y
E227: c = a|b
E228: msg = fmt%(errno, errmsg)
"""
parens = 0
need_space = False
prev_type = tokenize.OP
prev_text = prev_end = None
for token_type, text, start, end, line in tokens:
if token_type in SKIP_COMMENTS:
continue
if text in ('(', 'lambda'):
parens += 1
elif text == ')':
parens -= 1
if need_space:
if start != prev_end:
# Found a (probably) needed space
if need_space is not True and not need_space[1]:
yield (need_space[0],
"E225 missing whitespace around operator")
need_space = False
elif text == '>' and prev_text in ('<', '-'):
# Tolerate the "<>" operator, even if running Python 3
# Deal with Python 3's annotated return value "->"
pass
else:
if need_space is True or need_space[1]:
# A needed trailing space was not found
yield prev_end, "E225 missing whitespace around operator"
elif prev_text != '**':
code, optype = 'E226', 'arithmetic'
if prev_text == '%':
code, optype = 'E228', 'modulo'
elif prev_text not in ARITHMETIC_OP:
code, optype = 'E227', 'bitwise or shift'
yield (need_space[0], "%s missing whitespace "
"around %s operator" % (code, optype))
need_space = False
elif token_type == tokenize.OP and prev_end is not None:
if text == '=' and parens:
# Allow keyword args or defaults: foo(bar=None).
pass
elif text in WS_NEEDED_OPERATORS:
need_space = True
elif text in UNARY_OPERATORS:
# Check if the operator is being used as a binary operator
# Allow unary operators: -123, -x, +1.
# Allow argument unpacking: foo(*args, **kwargs).
if (prev_text in '}])' if prev_type == tokenize.OP
else prev_text not in KEYWORDS):
need_space = None
elif text in WS_OPTIONAL_OPERATORS:
need_space = None
if need_space is None:
# Surrounding space is optional, but ensure that
# trailing space matches opening space
need_space = (prev_end, start != prev_end)
elif need_space and start == prev_end:
# A needed opening space was not found
yield prev_end, "E225 missing whitespace around operator"
need_space = False
prev_type = token_type
prev_text = text
prev_end = end