Question 7 Use a dictionary to count the frequency of letters in the input string. Only letters should be counted, not blank spaces, numbers, or punctuation. Upper case should be considered the same as lower case. For example, count_letters("This is a sentence.") should return {'t': 2, 'h': 1, 'i': 2, 's': 3, 'a': 1, 'e': 3, 'n': 2, 'c': 1}.

Strings_Lists_Dictionaries_7.py

def count_letters(text):
  result = {}
  text = text.lower()
  # Go through each letter in the text
  for letter in text:
    # Check if the letter needs to be counted or not
    if letter .isalpha() and letter not in result:
        result[letter] = text.lower().count(letter)
    # Add or increment the value in the dictionary
  return result

print(count_letters("AaBbCc"))
# Should be {'a': 2, 'b': 2, 'c': 2}

print(count_letters("Math is fun! 2+2=4"))
# Should be {'m': 1, 'a': 1, 't': 1, 'h': 1, 'i': 1, 's': 1, 'f': 1, 'u': 1, 'n': 1}

print(count_letters("This is a sentence."))
# Should be {'t': 2, 'h': 1, 'i': 2, 's': 3, 'a': 1, 'e': 3, 'n': 2, 'c': 1}

def count_letters(text):
result = {}
text = text.lower()

Go through each letter in the text

for letter in text:
    if letter in result:
        result[letter] += 1
    else:
        result[letter] = 1
# Check if the letter needs to be counted or not
# Add or increment the value in the dictionary
        
return result

print(count_letters("AaBbCc"))

Should be {'a': 2, 'b': 2, 'c': 2}

print(count_letters("Math is fun! 2+2=4"))

Should be {'m': 1, 'a': 1, 't': 1, 'h': 1, 'i': 1, 's': 1, 'f': 1, 'u': 1, 'n': 1}

print(count_letters("This is a sentence."))

Should be {'t': 2, 'h': 1, 'i': 2, 's': 3, 'a': 1, 'e': 3, 'n': 2, 'c': 1}