'int' object is not iterable

Question

7.3 and was wondering about why in the following example the string "racecar" is being treated as type int. Thanks in advance for any help

>>> 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

Solution 1

Because you need to use range(len(s)) to get a list of integers to iterate over (or xrange in Python 2.x).

Alternatively, you can use enumerate():

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

Or just not use an index in the first place:

for c in s:
    print(c)

Solution 2

You should do:

for i in xrange(len(s)):

Comments

[Tadeck]

It is not "string 'racecar'", it is "len(s)" that you want to iterate through. Result of "len(s)" is an int.

[Karl Knechtel]

+1 for not using an index. Seriously, where did you get the idea that you would want or need to use an index? From another programming language, presumably. Python is better than that.

[PM0087]

Just quickly running it, I got this error: NameError: name 'xrange' is not defined

[smichak]

Sounds like you're in Python3. Try range instead of xrange.