Game Development Reference
In-Depth Information
9 - Hangman
Replacing the Underscores with Correctly Guessed Letters
77. for i in range(len(secretWord)): # replace blanks
with correctly guessed letters
78. if secretWord[i] in correctLetters:
79. blanks = blanks[:i] + secretWord[i] + blanks
[i+1:]
Let's pretend the value of
secretWord
is
'otter'
and the value in
correctLetters
is
'tr'
. Then
len(secretWord)
will return
5
. Then
range
(len(secretWord))
becomes
range(5)
, which in turn returns the list
[0, 1, 2,
3, 4]
.
Because the value of
i
will take on each value in
[0, 1, 2, 3, 4]
, then the
for
loop code is equivalent to this:
if secretWord[0] in correctLetters:
blanks = blanks[:0] + secretWord[0] + blanks[1:]
if secretWord[1] in correctLetters:
blanks = blanks[:1] + secretWord[1] + blanks[2:]
if secretWord[2] in correctLetters:
blanks = blanks[:2] + secretWord[2] + blanks[3:]
if secretWord[3] in correctLetters:
blanks = blanks[:3] + secretWord[3] + blanks[4:]
if secretWord[4] in correctLetters:
blanks = blanks[:4] + secretWord[4] + blanks[5:]
(By the way, writing out the code like this is called
loop unrolling
.)
If you are confused as to what the value of something like
secretWord[0]
or
blanks[3:]
is, then look at this picture. It shows the value of the
secretWord
and
blanks
variables, and the index for each letter in the string.
Figure 9-2: The indexes of the
blanks
and
secretWord
strings.
