Convert_snake_case_to_PascalCase.py

def pascal_case(string):
    new_string = ''
    i = 0
    while i < len(string):
        if i == 0:
            new_string += string[i].upper()
        elif string[i] == '_': 
            new_string += string[i+1].upper()
            i += 1
        else:
            new_string += string[i]
        i += 1
    return new_string 

result = pascal_case('custom_date_builder')
print(result)