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Quick Python Bit #1

without comments

A student asked for a Python example that would find a string starting with a vowel and prepend an “An” or starting with a non-vowel and prepend an “A”. As a rule, this one seems to make sense to most beginning programmers.

#/usr/bin/python
 
# Import the regular expression library.
import re
 
# Create a list of words to check.
haystack = ['anything','something','nothing']
 
# Create a regular expression for a leading vowel.
needle = "^[AEIOUaeiou].*$"
 
# Read through the haystacks and use the right article. 
for i in range(0,len(haystack),1):
  if re.search(needle,haystack[i],re.IGNORECASE):
    print("An",haystack[i]+".")
  else:
    print("A",haystack[i]+".")

However, this loop is much cleaner:

#/usr/bin/python
 
# Import the regular expression library.
import re
 
# Create a list of words to check.
haystack = ['anything','something','nothing']
 
# Create a regular expression for a leading vowel.
needle = "^[AEIOUaeiou].*$"
 
# Read through the haystacks and use the right article. 
for i in haystack:
  if re.search(needle,i,re.IGNORECASE):
    print("An",i+".")
  else:
    print("A",i+".")

Both programs print the following:

An anything.
A something.
A nothing.

As always, happy to help write another example.

Written by maclochlainn

October 26th, 2022 at 11:32 pm

Posted in Python,Python 3.x

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