Writing a recursive case

Question

How do I complete this recursive function at output_string += ? Output should be: 5! = 5 * 4 * 3 * 2 * 1 = 120

def print_factorial(fact_counter, fact_value):
    output_string = ''

    if fact_counter == 0:      # Base case: 0! = 1
        output_string += '1'
    elif fact_counter == 1:    # Base case: print 1 and result
        output_string += str(fact_counter) +  ' = ' + str(fact_value)
    else:                       # Recursive case
        output_string += str(fact_counter) + ' * '
        next_counter = fact_counter - 1
        next_value = next_counter * fact_value
        output_string += 

    return output_string

user_val = 5
print('%d! = ' % user_val, end="")
print(print_factorial(user_val, user_val))

Answer 1

def print_factorial(fact_counter, fact_value):
output_string = ''

if fact_counter == 0:      # Base case: 0! = 1 #This line will never execute, no recursive call will ever be made with fact_counter = 0 and there shouldn't be anyways, so its harmless.
    output_string += '1'
elif fact_counter == 1:    # Base case: print 1 and result
    output_string += str(fact_counter) +  ' = ' + str(fact_value) 
else:                       # Recursive case
    output_string += str(fact_counter) + ' * '
    next_counter = fact_counter - 1
    next_value = next_counter * fact_value
    output_string += print_factorial(next_counter, next_value) 

return output_string

user_val = 5
print('%d! = ' % user_val, end="")
print(print_factorial(user_val, user_val))

You needed to compute the next number in the factorial then add it with "*" too. So a recursive call should be made at the concatenation statement.

Umm, if fact_counter == 0, will NEVER execute and I've written a comment to point this out inside the code.