Assert断言

Assert断言

环境

Python3.7.0

macOS High Sierra 10.13.6

python assert断言是声明其布尔值必须为真的判定,如果发生异常就说明表达式为假.可以理解assert断言语句为raise-if-not,用来测试表达式，返回为假就会触发异常

>>> assert 1==1
>>> assert 1==0
Traceback (most recent call last):
  File "", line 1, in 
AssertionError

使用assert可以判断条件是否正确

try:
    assert 1==0
except AssertionError as e:
    print(e.args)

()