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Python

Shea Taylor
PLUS
Shea Taylor
Courses Plus Student 664 Points
Posted by Shea Taylor
Shea Taylor
Courses Plus Student 664 Points

Kenneth Love's Devowel script

I'm a little confused regarding a few keywords in this script. Full script:

state_names = ["Alabama", "California", "Oklahoma", "Florida"]
vowels = list('aeiou')
output = []

for state in state_names:
  state_list = list(state.lower())

  for vowel in vowels:
    while True:
      try:
        state_list.remove(vowel)
      except:
        break
  output.append(''.join(state_list).capitalize())

print(output)

This specific part (code modified to assist the question). Why does this print out the states in a list when we haven't defined what state is?:

state_names = ["Alabama", "California", "Oklahoma", "Florida"]
vowels = list('aeiou')
output = []

for state in state_names:
  print(state)

Also, same instance here. Does Python know what vowel means? I'm not sure why this is working since we haven't defined the word vowel.:

  for vowel in vowels:
    while True:
      try:
        state_list.remove(vowel)
      except:
        break

Just trying to wrap my head around the details. Any clarification would be much appreciated.

(Kenneth Love )

1 Answer

Ken Alger
STAFF
Ken Alger
Treehouse Teacher
Ken Alger
Ken Alger
Treehouse Teacher

Shea;

Welcome to Treehouse!

You ask some great questions about for loops. The variable names Kenneth decided to use, state and vowel could have been anything. Python’s for statement iterates over the items of any sequence (a list or a string), in the order that they appear in the sequence. The iteration variable, state and vowel in these instances, are essentially a holder variable. As stated, they could have been named x and y, or python and java, or cat and dog. However, using variable names that have meaning to the situation helps everyone understand what is going on.

In the state_names example, the for loop goes through each item in the state_names list and does something with it. So the first iteration through the for loop, state will have a value of "Alabama", the second time through "California", etc. The same thing holds true for the for loop with vowel.

See how the naming convention Kenneth used helps? If he had used x and y, which is popular with some people, it wouldn't be nearly as readable or understandable.

Post back if you are still stuck.

Happy coding,

Ken

Shea Taylor
Shea Taylor
Courses Plus Student 664 Points
Shea Taylor
Shea Taylor
Courses Plus Student 664 Points

Ken Alger That makes perfect since! The for loop is much less mysterious now. Thank you!