CODEWITHSUNDEEP
pythonfrequency
Marisa
Marisa

Reputation: 77

How do I count the amount of times a letter appears using python?

I'm trying to count how many times a letter appears in my list. However, whenever I use the count function and input the letter I want to count my return = 0

This is the code: 

lab7 =    ['Euclid','Archimedes','Newton','Descartes','Fermat','Turing','Euler','Einstein','Boole','Fibonacci', 'Nash']

print(lab7[1])   #display longest name - a

print(lab7[10])  #display shortest name - b

c = [ word[0] for word in lab7]    
#display str that consists of 1st letter from each name in list - c
print(c)

d = [ word[-1] for word in lab7]
#display str that consists of last letter from each name in list - d
print(d)

**x = input('Enter letter you would like to count here')
lab7.count('x')
e = lab7.count('x')
print(e)**

This is the part of the code that is not working. I keep getting ->

Archimedes
Nash
['E', 'A', 'N', 'D', 'F', 'T', 'E', 'E', 'B', 'F', 'N']
['d', 's', 'n', 's', 't', 'g', 'r', 'n', 'e', 'i', 'h']
Enter letter you would like to count here s
0

As my output.

Upvotes: 3

Views: 1460

Answers (4)

DevLounge
DevLounge

Reputation: 8447

You can also use sum + a generator:

letter = letter.lower()
count = sum(w.lower().count(letter) for w in lab7)

Upvotes: 0

Spherical Cowboy
Spherical Cowboy

Reputation: 566

lst = ['Euclid', 'Archimedes', 'Newton', 'Descartes', 'Fermat',
       'Turing', 'Euler', 'Einstein', 'Boole', 'Fibonacci', 'Nash']

letter = input("Enter the letter you would like to count: ")

count = "".join(lst).lower().count(letter)

print(count)

Which will join all words contained in the list and results in a single string. The string will then be lowered in order to count both uppercase and lowercase letters (e.g. A being equal to a). If uppercase and lowercase letter should not be treated equally, .lower() can be removed.

To check if the input is only a single letter:

lst = ['Euclid', 'Archimedes', 'Newton', 'Descartes', 'Fermat',
       'Turing', 'Euler', 'Einstein', 'Boole', 'Fibonacci', 'Nash']

letter = input("Enter the letter you would like to count: ")

while not letter.isalpha() or len(letter) != 1:
    letter = input("Not a single letter. Try again: ")

print("".join(lst).lower().count(letter))

Upvotes: 1

nico
nico

Reputation: 2121

@ZdaR's solution Is best if you want to count the letters just once. If you want to get the letters more than once on the same string it will be faster to use the collection.Counter. Example:

from collections import Counter 

counter = Counter("".join(lab7))
while True:
    input_char = input('Enter letter you would like to count here')
    print counter[input_char]

Upvotes: 1

ZdaR
ZdaR

Reputation: 22964

If you want to count the occurences of a given character among all the words in the list then you may try:

input_char = input('Enter letter you would like to count here')
print "".join(lab7).count(input_char)

If you want the logic to be case-insensetive, the you may convert the input character to lower case using .lower()

You First concatenate all the elements of list to get a unified string and then use the count method to get the occurences of a given character.

Upvotes: 4

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