Given a string, the task is to pad string up to given specific length with whitespaces. Let’s discuss few methods to solve the given task.
Method #1: Using ljust()
Python3
# Python code to demonstrate# pad spaces in string# upto fixed length# initialising stringini_string = "123abcjw"padding_size = 15# printing string and its lengthprint ("initial string : ", ini_string, len(ini_string))# code to pad spaces in stringres = ini_string.ljust(padding_size)# printing string and its lengthprint ("final string : ", res, len(res)) |
Output:
initial string : 123abcjw 8 final string : 123abcjw 15
Method #2: Using format
Python3
# Python code to demonstrate# pad spaces in string# upto fixed length# initialising stringini_string = "123abcjw"# printing string and its lengthprint ("initial string : ", ini_string, len(ini_string))# code to pad spaces in stringres = "{:<15}".format(ini_string)# printing string and its lengthprint ("final string : ", res, len(res)) |
Output:
initial string : 123abcjw 8 final string : 123abcjw 15
Method #3: Using operators( * and +)
Python3
# Python code to demonstrate# pad spaces in string# upto fixed length# initialising stringini_string = "123abcjw"padding_size = 15# printing string and its lengthprint ("initial string : ", ini_string, len(ini_string))# code to pad spaces in stringres = ini_string + " "*(padding_size - len(ini_string))# printing string and its lengthprint ("final string : ", res, len(res)) |
Output:
initial string : 123abcjw 8 final string : 123abcjw 15
Method#4: Using f-strings
Algorithm:
- Initialize a string ‘ini_string‘ with a value.
- Calculate the length of ‘ini_string’ using the ‘len()’ function.
- Print the initial string and its length using the ‘print()’ function and f-strings.
- Use the ‘f-string’ with format specifier ‘{:<N}’ to left justify the ‘ini_string’ and pad it with spaces on the right side upto ‘padding_size’ length.
- Store the resulting string in a new variable ‘res’.
- Print the final string and its length using the ‘print()’ function and f-strings.
Python3
# initialising stringini_string = "123abcjw:, .@! eiw"# create a char array from input string# Python code to demonstrate# padding a string upto fixed length using f-strings# initialising stringini_string = "123abcjw"padding_size = 15# printing string and its lengthprint(f"initial string : {ini_string} {len(ini_string)}")# code to pad spaces in stringres = f"{ini_string:<{padding_size}}"# printing string and its lengthprint(f"final string : {res} {len(res)}") |
Output
initial string : 123abcjw 8 final string : 123abcjw 15
Time Complexity: The time complexity of the algorithm is O(1) as it does not depend on the length of the input string. The ‘len()’ function, f-string formatting, and string concatenation all have constant time complexity.
Space Complexity: The space complexity of the algorithm is O(1) as it only uses a fixed amount of memory to store the input string, padding size, and resulting string.
