I am trying to understand the behavior of the code below. When I increase the number in the first curly braces, I get extra whitespace to the left of the first column. When I do it for the second number, I also get extra whitespace, but to the left of the second column. However, when I do it for the third one, nothing changes. Why?
w = ['storm', 'ubuntu', 'singular', 'pineapple']
for i, word in enumerate(w):
word_index = 3
print('{:2} {:1} {:6}'.format(i, word_index, word))
Numbers pad left by default, but strings pad right (docs):
>>> "{:3}".format(1)
' 1'
>>> "{:3}".format("1")
'1 '
If you want the string to align right too, specify it:
>>> "{:>3}".format("1")
' 1'
Note that "storm" (length 5) does actually get an extra trailing space when padded to width 6, but since it was printed on the right you probably wouldn't notice.
Something actually does change, but you cannot see it. Let's use a slightly modified version of your code, that marks the margins of the output:
w = ['storm', 'ubuntu', 'singular', 'pineapple']
for i, word in enumerate(w):
word_index = 3
print('>>{:2} {:1} {:6}<<'.format(i, word_index, word))
When you run this, you'll get:
>> 0 3 storm <<
>> 1 3 ubuntu<<
>> 2 3 singular<<
>> 3 3 pineapple<<
Now, let's change the third width to 16:
w = ['storm', 'ubuntu', 'singular', 'pineapple']
for i, word in enumerate(w):
word_index = 3
# Changed width of 3rd field from 6 to 16
print('>>{:2} {:1} {:16}<<'.format(i, word_index, word))
Running this will give more white space after the last field:
>> 0 3 storm <<
>> 1 3 ubuntu <<
>> 2 3 singular <<
>> 3 3 pineapple <<
