'''
URLify:
Write a method to replace all spaces in a string with '%20'. You many assume that the string has sufficent space
at the end to hold the additional characters, and that you are given the "true" length of the string.
'''

def URLify(str1):

    return url

def main():

    str1 = "hello world"
    print( "URLify: " + str(URLify(str1)) )

if __name__ == "__main__":
    main()