Python: Convert a given string to Camelcase

Last update on June 12 2025 12:41:36 (UTC/GMT +8 hours)

Convert string to CamelCase.

From Wikipedia,
Camel case (sometimes stylized as camelCase or CamelCase; also known as camel caps or more formally as medial capitals) is the practice of writing phrases without spaces or punctuation, indicating the separation of words with a single capitalized letter, and the first word starting with either case.

Write a Python program to convert a given string to Camelcase.

• Use re.sub() to replace any - or _ with a space, using the regexp r"(_|-)+".
• Use str.title() to capitalize the first letter of each word and convert the rest to lowercase.
• Finally, use str.replace() to remove spaces between words.

Sample Solution:

Python Code:

# Import the 'sub' function from the 're' module for regular expression substitution
from re import sub

# Define a function to convert a string to camel case
def camel_case(s):
    # Use regular expression substitution to replace underscores and hyphens with spaces,
    # then title case the string (capitalize the first letter of each word), and remove spaces
    s = sub(r"(_|-)+", " ", s).title().replace(" ", "")
    
    # Join the string, ensuring the first letter is lowercase
    return ''.join([s[0].lower(), s[1:]])

# Test the function with different input strings and print the results
print(camel_case('JavaScript'))
print(camel_case('Foo-Bar'))
print(camel_case('foo_bar'))
print(camel_case('--foo.bar'))
print(camel_case('Foo-BAR'))
print(camel_case('fooBAR'))
print(camel_case('foo bar')) 

Sample Output:

javascript
fooBar
fooBar
foo.Bar
fooBar
foobar
fooBar

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to convert a space-separated string into CamelCase by capitalizing each word except the first.
• Write a Python program to implement a function that converts an underscore-separated string into CamelCase.
• Write a Python program to transform a string with mixed delimiters into CamelCase using regular expressions.
• Write a Python program to create a function that takes a sentence and returns it in CamelCase format by concatenating words.

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