Python: Add leading zeroes to a string

Last update on April 16 2025 13:04:34 (UTC/GMT +8 hours)

Add Leading Zeroes

Write a Python program to add leading zeroes to a string.

Pictorial Presentation:

Sample Solution-1:

Python Code:

# Define the original string 'str1'.
str1 = '122.22'
print("Original String: ", str1)

# Print a message to indicate the purpose of the code.
print("\nAdded trailing zeros:")

# Use the 'ljust' method to add trailing zeros to 'str1' to make its total width 8.
str1 = str1.ljust(8, '0')
print(str1)

# Repeat the process to make the total width 10.
str1 = str1.ljust(10, '0')
print(str1)

# Print a message to indicate the addition of leading zeros.
print("\nAdded leading zeros:")

# Reset 'str1' to the original value.
str1 = '122.22'

# Use the 'rjust' method to add leading zeros to 'str1' to make its total width 8.
str1 = str1.rjust(8, '0')
print(str1)

# Repeat the process to make the total width 10.
str1 = str1.rjust(10, '0')
print(str1)

Sample Output:

Original String:  122.22

Added trailing zeros:
122.2200
122.220000

Added leading zeros:
00122.22
0000122.22

Sample Solution-2:

Python Code:

# Define the original string 'str1'.
str1 = '122.22'
print("Original String: ", str1)

# Print a message to indicate the purpose of the code.
print("\nAdded trailing zeros:")

# Define a format text with left alignment and total width of 8.
f_text = '{:<08}'

# Use the 'format' method to add trailing zeros to 'str1' according to the format text.
str1 = f_text.format(str1)
print(str1)

# Define a format text with left alignment and total width of 10.
f_text = '{:<010}'

# Repeat the process to make the total width 10.
str1 = f_text.format(str1)
print(str1)

# Print a message to indicate the addition of leading zeros.
print("\nAdded leading zeros:")

# Reset 'str1' to the original value.
str1 = '122.22'

# Define a format text with right alignment and total width of 8.
f_text = '{:>08}'

# Use the 'format' method to add leading zeros to 'str1' according to the format text.
str1 = f_text.format(str1)
print(str1)

# Define a format text with right alignment and total width of 10.
f_text = '{:>010}'

# Repeat the process to make the total width 10.
str1 = f_text.format(str1)
print(str1)

Sample Output:

Original String:  122.22

Added trailing zeros:
122.2200
122.220000

Added leading zeros:
00122.22
0000122.22

For more Practice: Solve these Related Problems:

Write a Python function to pad a number with leading zeros until it reaches a specified length.
Write a Python program to format an integer as a fixed-length string with leading zeros.
Write a Python program to add leading zeros to hexadecimal numbers.
Write a Python program to add leading zeros dynamically based on input length.

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