user
How to append a character n times to a string?
alphonsio

Appending a character multiple times to a string in Python can be easily achieved by using string multiplication and concatenation:

>>> 'a'*7
'aaaaaaa'

Here’s how you can do it:

Method 1: Using String Multiplication

Python allows you to "multiply" a string by an integer, which duplicates the string that many times.

original_str = "hello"
char_to_append = 'a'
times = 3  # Number of times to append

# Append character 'a' three times to the string "hello"
new_str = original_str + (char_to_append * times)

print(new_str)  # Output: helloaaa

Explanation:

  • char_to_append * times creates a string where the character char_to_append is repeated times times.
  • original_str + ... concatenates the original string with the new repeated characters.

Method 2: Using a Loop

While not as efficient for this specific use case, you can also append characters using a loop, which might be more intuitive if coming from other programming languages.

original_str = "hello"
char_to_append = 'a'
times = 3

# Start with the original string
new_str = original_str

# Loop to append the character 'a' three times
for _ in range(times):
    new_str += char_to_append

print(new_str)  # Output: helloaaa

Method 3: Using a Join with List Comprehension

This method involves creating a list of the character repeated times times and then joining it with the original string. It's more Pythonic and can be useful in more complex string operations.

original_str = "hello"
char_to_append = 'a'
times = 3

# Use join on an empty string with a list comprehension for the repeated character
new_str = original_str + ''.join([char_to_append for _ in range(times)])

print(new_str)  # Output: helloaaa

Choosing a Method:

  • String multiplication: Fastest and most readable for simple repetitions.
  • Loop: More control over the process; useful if the logic for appending might change based on some conditions.
  • Join and List Comprehension: Offers flexibility, good for more complex constructions or when working with lists.

String multiplication is generally the best option for simple character repetitions due to its simplicity and efficiency.