我仍然处于学习Python的早期阶段,并且已经涉及这个语法,但我不知道它的作用。逗号跟随变量赋值如何连接?
check, expression = expression, expression.replace('()', '').replace('[]', '').replace('{}', '')
现在我知道str.replace()函数做什么,我在到底是怎么被“检查”被分配给该级联替换功能的只是不清楚。
语境:
这里是上下文完整的代码,它的目的只是为了请检查是否括号被正确使用给定的字符串:
BRACKETS = ("{","[","(","}","]",")")
list = []
#Creating a list with only the brackets in it.
for c in expression:
if (c in BRACKETS) and (c in expression):
list.append(c)
expression = ''.join(list)
while expression:
check, expression = expression, expression.replace('()', '').replace('[]', '').replace('{}', '')
if expression == check:
return False
return True
将'expression'的值赋给'check',而将'expression.replace ...'的值赋给'expression'。例如,如果你做'a,b = 1,2',那么a得到1,b得到2. –