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# pylint: disable=print-statement
"""Tests for loopvar-in-closure."""
from __future__ import print_function
def good_case():
"""No problems here."""
lst = []
for i in range(10):
lst.append(i)
def good_case2():
"""No problems here."""
return [i for i in range(10)]
def good_case3():
"""No problems here."""
lst = []
for i in range(10): # [unused-variable]
lst.append(lambda i=i: i)
def good_case4():
"""No problems here."""
lst = []
for i in range(10):
print(i)
lst.append(lambda i: i)
def good_case5():
"""No problems here."""
return (i for i in range(10))
def good_case6():
"""Accept use of the variable after the loop.
There's already a warning about possibly undefined loop variables, and
the value will not change any more."""
for i in range(10):
print(i)
return lambda: i # [undefined-loop-variable]
def good_case7():
"""Accept use of the variable inside return."""
for i in range(10):
if i == 8:
return lambda: i
return lambda: -1
def good_case8():
"""Lambda defined and called in loop."""
for i in range(10):
print((lambda x: i + x)(1))
def good_case9():
"""Another eager binding of the cell variable."""
funs = []
for i in range(10):
def func(bound_i=i):
"""Ignore."""
return bound_i
funs.append(func)
return funs
def bad_case():
"""Closing over a loop variable."""
lst = []
for i in range(10):
print(i)
lst.append(lambda: i) # [cell-var-from-loop]
def bad_case2():
"""Closing over a loop variable."""
return [lambda: i for i in range(10)] # [cell-var-from-loop]
def bad_case3():
"""Closing over variable defined in loop."""
lst = []
for i in range(10):
j = i * i
lst.append(lambda: j) # [cell-var-from-loop]
return lst
def bad_case4():
"""Closing over variable defined in loop."""
lst = []
for i in range(10):
def nested():
"""Nested function."""
return i**2 # [cell-var-from-loop]
lst.append(nested)
return lst
def bad_case5():
"""Problematic case.
If this function is used as
>>> [x() for x in bad_case5()]
it behaves 'as expected', i.e. the result is range(10).
If it's used with
>>> lst = list(bad_case5())
>>> [x() for x in lst]
the result is [9] * 10 again.
"""
return (lambda: i for i in range(10)) # [cell-var-from-loop]
def bad_case6():
"""Closing over variable defined in loop."""
lst = []
for i, j in zip(range(10), range(10, 20)):
print(j)
lst.append(lambda: i) # [cell-var-from-loop]
return lst
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