Program that takes sentence as input from the user and computes the frequency of each letter. Use a variable of dictionary type to maintain and show the frequency of each letter

Write a program that takes sentence as input from the user and computes the frequency of each letter. Use a variable of dictionary type to maintain and show the frequency of each letter

st = input("Enter the string: ")
d = dict()
for c in st:
    if c in d:
        d[c] = d[c] + 1
    else:
        d[c] = 1
print(d)

Output:
{'h': 1, 'e': 1, 'l': 2, 'o': 1}

The provided Python code counts the frequency of each character in a given string and stores the counts in a dictionary. Here’s a detailed explanation of how the code works:

Explanation

1. Prompt for Input:

   st = input("Enter the string: ")

• This line prompts the user to enter a string and stores it in the variable st.

1. Initialize an Empty Dictionary:

   d = dict()

• An empty dictionary d is created. This dictionary will store characters as keys and their counts as values.

1. Iterate Over Each Character in the String:

   for c in st:

• A for loop iterates over each character c in the input string st.

1. Update Character Counts:

   if c in d:
       d[c] = d[c] + 1
   else:
       d[c] = 1

• Inside the loop, an if-else statement checks if the character c is already a key in the dictionary d.
  • If c is in the dictionary, its count is incremented by 1 (d[c] = d[c] + 1).
  • If c is not in the dictionary, it is added as a key with a count of 1 (d[c] = 1).

1. Print the Result:

   print(d)

• After the loop completes, the dictionary d, which now contains the frequency of each character, is printed.

Example

Let’s go through an example where the user inputs a string. Suppose the user inputs the following string:

Enter the string: hello

The code execution will be as follows:

• Input String:

  st = "hello"

• Initialize Dictionary:

  d = {}

• Iterate and Update Counts:
• For c = 'h': d becomes {'h': 1}
• For c = 'e': d becomes {'h': 1, 'e': 1}
• For c = 'l': d becomes {'h': 1, 'e': 1, 'l': 1}
• For c = 'l': d becomes {'h': 1, 'e': 1, 'l': 2}
• For c = 'o': d becomes {'h': 1, 'e': 1, 'l': 2, 'o': 1}
• Resulting Dictionary:

  {'h': 1, 'e': 1, 'l': 2, 'o': 1}

Full Code

Here is the complete code for reference:

st = input("Enter the string: ")
d = dict()
for c in st:
    if c in d:
        d[c] = d[c] + 1
    else:
        d[c] = 1
print(d)

Output

For the input "hello", the output will be:

{'h': 1, 'e': 1, 'l': 2, 'o': 1}

Summary

This code effectively counts the frequency of each character in a given string and stores the results in a dictionary, which is then printed. Each character from the string is either added to the dictionary with a count of 1 if it is encountered for the first time or has its count incremented by 1 if it is already present in the dictionary.