beginner here. Trying to figure out how I can define a function that counts the total number of occurrences of certain characters in a string. Say, we want to count the number of occurrences of the letters a and b. I need to do it within a for loop. What I have so far is this. Please let me know what I can do to make this work!
#define functions
def ch_count(word):
total=0
for letter in word:
if letter==L1:
total=total+1
return total
#main program
L1=["a","e","y"]
print(ch_count("Merry Christmas")
You can try using a default dictionary. Unlike a normal dictionary, it provides a default value is a key does not exist in a dictionary.
from collections import defaultdict
string = 'quick brown fox'
letter_count = defaultdict(int)
for letter in string:
letter_count[letter] += 1
print(letter_count)
You can use sum
:
string = 'Some test string'
c = 'a'
sum(x == c for x in string)
Checking for multiple characters instead:
c = 'abc'
sum(x in c for x in string)
Or you can use collections.Counter
to find the count of each character:
from collections import Counter
counts = Counter(string)
counts[letter]
you could write a function which takes 2 arguments. The string to check, and the letter that we want to use to count occurrencies in the string.
# I will use a as a default letter
def count_occurrencies(s, letter='a'):
return sum([i == letter for i in s])
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