Python: Check if a given string contains two similar consecutive letters

Last update on April 17 2025 13:05:11 (UTC/GMT +8 hours)

Consecutive Similar Letters

Write a Python program to check if a given string contains two similar consecutive letters.

Sample Solution-1:

Python Code:

# Define a function 'test' that checks if there are consecutive similar letters in a string.
def test(input_str):
    # Use the 'any' function along with a generator expression to check for consecutive similar letters using 'zip'.
    return any(c1 == c2 for c1, c2 in zip(input_str, input_str[1:]))

# Test the 'test' function with different input strings.
str1 = "PHP"
print("Original string: ", str1)
print("Check for consecutive similar letters! ", test(str1))

str2 = "PHHP"
print("\nOriginal string: ", str2)
print("Check for consecutive similar letters! ", test(str2))

str3 = "PHPP"
print("\nOriginal string: ", str3)
print("Check for consecutive similar letters! ", test(str3))

Sample Output:

Original string:  PHP
Check for consecutive similar letters!  False

Original string:  PHHP
Check for consecutive similar letters!  True

Original string:  PHPP
Check for consecutive similar letters!  True

Explanation:

Here is a breakdown of the above Python code:

Test Function (test function):

The "test()" function is defined to check if there are consecutive similar letters in a given string.
It uses the "any()" function with a generator expression inside 'zip' to compare each character with its consecutive character in the string.

Flowchart:

Sample Solution-2:

Python Code:

# Define a function 'test' that checks if there are consecutive similar letters in a string.
def test(input_str):
    # Iterate through each character in the input string.
    for el in input_str:
        # Check if the current character repeated twice is present in the input string.
        if el * 2 in input_str:
            return True
    # If no consecutive similar letters are found, return False.
    return False

# Test the 'test' function with different input strings.
str1 = "PHP"
print("Original string: ", str1)
print("Check for consecutive similar letters! ", test(str1))

str2 = "PHHP"
print("\nOriginal string: ", str2)
print("Check for consecutive similar letters! ", test(str2))

str3 = "PHPP"
print("\nOriginal string: ", str3)
print("Check for consecutive similar letters! ", test(str3))

Sample Output:

Original string:  PHP
Check for consecutive similar letters!  False

Original string:  PHHP
Check for consecutive similar letters!  True

Original string:  PHPP
Check for consecutive similar letters!  True

Explanation:

Here is a breakdown of the above Python code:

Test Function (test function):

The "test()" function is defined to check if there are consecutive similar letters in a given string.
It iterates through each character in the input string and checks if the character repeated twice is present in the string.

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to check if a string contains any consecutive identical characters.
Write a Python program to determine whether a string has adjacent duplicate letters using iteration.
Write a Python program to scan a string and return True if any two successive characters are the same.
Write a Python program to iterate through a string and detect the presence of consecutive repeating letters.

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Python Code Editor:

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