diff options
Diffstat (limited to 'tests/functional/u/use/use_implicit_booleaness_not_len.py')
| -rw-r--r-- | tests/functional/u/use/use_implicit_booleaness_not_len.py | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/tests/functional/u/use/use_implicit_booleaness_not_len.py b/tests/functional/u/use/use_implicit_booleaness_not_len.py new file mode 100644 index 000000000..b4107ac2d --- /dev/null +++ b/tests/functional/u/use/use_implicit_booleaness_not_len.py @@ -0,0 +1,190 @@ +# pylint: disable=too-few-public-methods,import-error, missing-docstring, misplaced-comparison-constant +# pylint: disable=useless-super-delegation,wrong-import-position,invalid-name, wrong-import-order, condition-evals-to-constant + +if len('TEST'): # [use-implicit-booleaness-not-len] + pass + +if not len('TEST'): # [use-implicit-booleaness-not-len] + pass + +z = [] +if z and len(['T', 'E', 'S', 'T']): # [use-implicit-booleaness-not-len] + pass + +if True or len('TEST'): # [use-implicit-booleaness-not-len] + pass + +if len('TEST') == 0: # Should be fine + pass + +if len('TEST') < 1: # Should be fine + pass + +if len('TEST') <= 0: # Should be fine + pass + +if 1 > len('TEST'): # Should be fine + pass + +if 0 >= len('TEST'): # Should be fine + pass + +if z and len('TEST') == 0: # Should be fine + pass + +if 0 == len('TEST') < 10: # Should be fine + pass + +if 0 < 1 <= len('TEST') < 10: # Should be fine + pass + +if 10 > len('TEST') != 0: # Should be fine + pass + +if 10 > len('TEST') > 1 > 0: # Should be fine + pass + +if 0 <= len('TEST') < 100: # Should be fine + pass + +if z or 10 > len('TEST') != 0: # Should be fine + pass + +if z: + pass +elif len('TEST'): # [use-implicit-booleaness-not-len] + pass + +if z: + pass +elif not len('TEST'): # [use-implicit-booleaness-not-len] + pass + +while len('TEST'): # [use-implicit-booleaness-not-len] + pass + +while not len('TEST'): # [use-implicit-booleaness-not-len] + pass + +while z and len('TEST'): # [use-implicit-booleaness-not-len] + pass + +while not len('TEST') and z: # [use-implicit-booleaness-not-len] + pass + +assert len('TEST') > 0 # Should be fine + +x = 1 if len('TEST') != 0 else 2 # Should be fine + +f_o_o = len('TEST') or 42 # Should be fine + +a = x and len(x) # Should be fine + +def some_func(): + return len('TEST') > 0 # Should be fine + +def github_issue_1325(): + l = [1, 2, 3] + length = len(l) if l else 0 # Should be fine + return length + +def github_issue_1331(*args): + assert False, len(args) # Should be fine + +def github_issue_1331_v2(*args): + assert len(args), args # [use-implicit-booleaness-not-len] + +def github_issue_1331_v3(*args): + assert len(args) or z, args # [use-implicit-booleaness-not-len] + +def github_issue_1331_v4(*args): + assert z and len(args), args # [use-implicit-booleaness-not-len] + +b = bool(len(z)) # [use-implicit-booleaness-not-len] +c = bool(len('TEST') or 42) # [use-implicit-booleaness-not-len] + +def github_issue_1879(): + + class ClassWithBool(list): + def __bool__(self): + return True + + class ClassWithoutBool(list): + pass + + class ChildClassWithBool(ClassWithBool): + pass + + class ChildClassWithoutBool(ClassWithoutBool): + pass + + assert len(ClassWithBool()) + assert len(ChildClassWithBool()) + assert len(ClassWithoutBool()) # [use-implicit-booleaness-not-len] + assert len(ChildClassWithoutBool()) # [use-implicit-booleaness-not-len] + assert len(range(0)) # [use-implicit-booleaness-not-len] + assert len([t + 1 for t in []]) # [use-implicit-booleaness-not-len] + assert len(u + 1 for u in []) # [use-implicit-booleaness-not-len] + assert len({"1":(v + 1) for v in {}}) # [use-implicit-booleaness-not-len] + assert len(set((w + 1) for w in set())) # [use-implicit-booleaness-not-len] + + # pylint: disable=import-outside-toplevel + import numpy + numpy_array = numpy.array([0]) + if len(numpy_array) > 0: + print('numpy_array') + if len(numpy_array): + print('numpy_array') + if numpy_array: + print('b') + + import pandas as pd + pandas_df = pd.DataFrame() + if len(pandas_df): + print("this works, but pylint tells me not to use len() without comparison") + if len(pandas_df) > 0: + print("this works and pylint likes it, but it's not the solution intended by PEP-8") + if pandas_df: + print("this does not work (truth value of dataframe is ambiguous)") + + def function_returning_list(r): + if r==1: + return [1] + return [2] + + def function_returning_int(r): + if r==1: + return 1 + return 2 + + # def function_returning_generator(r): + # for i in [r, 1, 2, 3]: + # yield i + + # def function_returning_comprehension(r): + # return [x+1 for x in [r, 1, 2, 3]] + + # def function_returning_function(r): + # return function_returning_generator(r) + + assert len(function_returning_list(z)) # [use-implicit-booleaness-not-len] + assert len(function_returning_int(z)) + # This should raise a use-implicit-booleaness-not-len once astroid can infer it + # See https://github.com/PyCQA/pylint/pull/3821#issuecomment-743771514 + # assert len(function_returning_generator(z)) + # assert len(function_returning_comprehension(z)) + # assert len(function_returning_function(z)) + + +def github_issue_4215(): + # Test undefined variables + # https://github.com/PyCQA/pylint/issues/4215 + if len(undefined_var): # [undefined-variable] + pass + if len(undefined_var2[0]): # [undefined-variable] + pass + +# pylint: disable=len-as-condition + +if len('TEST'): + pass |