"Solving the TypeError: Unsupported Operand Type(s) for -: 'str' and 'int'"

When attempting to code in Python, it's not uncommon to encounter errors like the "TypeError: unsupported operand type(s) for -: 'str' and 'int'" error. This error typically occurs when attempting to perform mathematical operations on different data types, such as subtracting an integer from a string.

To understand this error, let's examine the code that led to it:

def cat_n_times(s, n):
    while s != 0:
        print(n)
        s = s - 1

text = input("What would you like the computer to repeat back to you: ")
num = input("How many times: ")

cat_n_times(num, text)

The issue here lies in the input function, which returns a string for both text and num. While the code attempts to subtract an integer (s - 1) from a string (num), resulting in the error.

Solution 1: Convert the Input

One solution is to convert the input from a string to an integer before performing mathematical operations. This can be done using the int() function:

num = int(input("How many times: "))

By converting num to an integer, we can ensure compatibility for mathematical operations with s.

Solution 2: Use Alternative Iteration

Instead of manually keeping track of indices, consider employing a more Pythonic approach for iteration:

def cat_n_times(s, n):
    for i in range(n):
        print(s)

text = input("What would you like the computer to repeat back to you: ")
num = int(input("How many times: "))

cat_n_times(text, num)

Here, the for loop with range(n) handles the iteration effectively.

API Considerations

The error also highlights potential issues with the API design. It may be more intuitive for text to be the string and num to represent the number of times. In this case, the API can be modified accordingly.