# Write a function that takes a string and a substring.
# Remove the substring from the string without using
# any built-in functions/methods besides len()
# (i.e., you may not use .index()).
# The function then returns the remaining string
#
# The substring will be at most one character long

def remove_string(string, substring):
    result = ""
    size = len(string)
    position = 0

    for position in range(0, size):
        if string[position] != substring:
            result += string[position]
        position += 1

    return result

print(remove_string("for loop, using range", "o"))