Python's pow function returns the result of raising a number to a given power. Define a function expo that performs this task, and state its computational complexity using big-O notation. The first argument of this function is the number, and the second argument is the exponent (nonnegative numbers only).
You may use either a loop or a recursive function in your implementation.
Caution: do not use Python's ** operator or pow function in this exercise!
def expo(base, exponent):
# Write your function here
def main():
for exponent in range(5):
print(exponent, expo(2, exponent))
if __name__ == "__main__":
main()