'int'对象不可迭代

Question

7.3并且想知道为什么在下面的例子中字符串"racecar"被视为int类型.在此先感谢您的帮助

>>> s = "racecar"

>>> for i in len(s):

    print(s[i]) 

Traceback (most recent call last):

  File "<pyshell#9>", line 1, in <module>

    for i in len(s):

TypeError: 'int' object is not iterable

Answer 1

因为您需要使用range(len(s))获取整数列表来迭代(或xrange在Python 2.x中).

或者,您可以使用enumerate():

for i, val in enumerate(s):
    print(i)
    print(val) # equivalent to s[i]

或者首先不使用索引:

for c in s:
    print(c)

Answer 2

你应该做：

for i in xrange(len(s)):