CODEWITHSUNDEEP
listpython-2.7dictionary
user3137869
user3137869

Reputation: 3

Python- Using dictionaries to compare two lists

Newbie to Python. i have been asked to write a function sameVowels(s1, s2), that given 2 strings s1,s2, returns True if both strings have exactly the same vowels (kind and number). (Think how to use dictionaries..)

I tried this:

import string
def sameVowels( s1 , s2 ) :
   d1 = {}
   d2 = {}
   vowels = [ 'a' , 'e' , 'i' , 'o' , 'u' ]

   for v1 in s1 :
      for k1 in vowels :
        if v1 == k1 :
            d1[k1] = v1

   for v2 in s2 :
      for k2 in vowels :
        if v2 == k2 :
            d2[k2] = v2
print d1
print d2
return d1 == d2

print sameVowels( 'aabcefiok' , 'xcexvcxaioa' )
print sameVowels( 'aabcefiok' , 'xcexvcxaioia' )

but what I get is:

{'a': 'a', 'i': 'i', 'e': 'e', 'o': 'o'}
{'a': 'a', 'i': 'i', 'e': 'e', 'o': 'o'}
True
{'a': 'a', 'i': 'i', 'e': 'e', 'o': 'o'}
{'a': 'a', 'i': 'i', 'e': 'e', 'o': 'o'}
True

the last pair should give False because the second string has an extra "i" I really dont know how to do it please help :)

Upvotes: 0

Views: 87

Answers (2)

Guy Sirton
Guy Sirton

Reputation: 8401

A somewhat simpler though less performant version (since we're counting each letter):

def sameVowels(s1,s2):
    vowels = [ 'a' , 'e' , 'i' , 'o' , 'u' ]
    f1 = dict((letter, s1.count(letter)) for letter in vowels)
    f2 = dict((letter, s2.count(letter)) for letter in vowels)
    return f1==f2

Another option:

from collections import Counter
def sameVowels(s1,s2):
    vowels = [ 'a' , 'e' , 'i' , 'o' , 'u' ]
    filtered1 = filter(lambda x: x in vowels, s1)
    filtered2 = filter(lambda x: x in vowels, s2)
    f1 = Counter(filtered1)
    f2 = Counter(filtered2)
    return f1==f2

Upvotes: 0

Christian Tapia
Christian Tapia

Reputation: 34146

You may want to store pairs like {vowel : ocurrences}, so try modifying the logic in your 2 for statements:

for v1 in s1 : # Iterate over string1
    if v1 in vowels: # Check if each letter is a vowel
        if v1 in d1: # If the vowel is in dict1
            d1[v1] += 1 # Add 1 to the actual value
        else: 
            d1[v1] = 1 # Add the vowel to dict1

The same for the second for:

for v2 in s2 :
    if v2 in vowels:
        if v2 in d2:
            d2[v2] += 1
        else:
            d2[v2] = 1

Upvotes: 1

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