Hangman question

[Peter Otten]

eschneider92 at comcast.net wrote:

> I'm  on chapter 9 of this guide to python:
> http://inventwithpython.com/chapter9.html     but I don't quite understand
> why line 79 is what it is (blanks = blanks[:i] + secretWord[i] +
> blanks[i+1:]). I particularly don't get the [i+1:] part. Any additional
> information and help would be greatly appreciated!

When you have a list with and want to replace the third item with something 
else you can do it like this:

>>> items = ["r", "e", "e", "d"]
>>> items[2] = "a"
>>> items
['r', 'e', 'a', 'd']

With a string that is not possible because strings cannot be modified (they 
are "immutable"):

>>> s = "reed"
>>> s[2] = "a"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'str' object does not support item assignment

You could try replace() to build a new string

>>> s.replace("e", "a")
'raad'

but that replaces all occurrences. So to manually replace th third character 
you take the first two characters of the original

>>> s[:2]
're'

then the characters after the third

>>> s[3:]
'd'

and finally build the new string by putting the new character (or string) in 
between:

>>> s[:2] + "a" + s[3:]
'read'

A function to replace the n-th character would then look like this:

>>> def replace_nth_char(s, n, replacement):
...     return s[:n] + replacement + s[n+1:]
... 
>>> replace_nth_char("read", 2, "e")
'reed'