How to take only integer input in Python

Mabel 18 Published: 12/16/2024

How to take only integer input in Python

I'd be happy to help! Here's how you can take only integer inputs in Python:

One way to ensure that the input is an integer is by using the built-in int() function. This function attempts to convert its argument into an integer. If the argument is not a valid integer, it will raise a ValueError.

Here's how you can use it:

num = int(input("Enter an integer: "))

print(num)

In this code, we're asking the user for input using the input() function. We then pass that input to the int() function and assign the result to the variable num. If the user enters something that can't be converted into an integer (like a string or a floating-point number), they will get an error message.

However, this approach has a drawback: if you're expecting only positive integers, and the user enters a negative integer, it will also work. For example:

num = int(input("Enter a positive integer: "))

print(num)

In this case, if the user enters a negative number (like -5), they'll get a ValueError because -5 is not an integer.

So, how can we ensure that only non-negative integers are accepted?

One way to do this is by using a while loop. Here's how:

num = None

while num < 0:


try:


num = int(input("Enter a non-negative integer: "))


except ValueError:


print("Invalid input! Please enter a non-negative integer.")


print(num)

In this code, we first set num to None. Then, inside the loop, we attempt to convert the user's input into an integer. If it fails (which means the input was not an integer), we catch the ValueError, print an error message, and ask for input again.

This process continues until the user enters a non-negative integer. Once they do, we break out of the loop and assign their input to num.

So, in summary: you can take only integer inputs in Python by using the int() function and catching any errors that occur if the user enters something that's not an integer. If you want to restrict the range of integers (like requiring them to be non-negative), you can use a while loop to keep asking for input until it meets the desired criteria.

Happy coding!

How do you get an integer type in Python?

I'm happy to respond in English!

In Python, an integer is a whole number without decimals. You can get an integer type in several ways:

By default: When you assign a whole number to a variable or use it as the result of a mathematical operation, it will be considered an integer: 
   x = 5

y = 3 + 2


print(x)  # Output: 5


print(y)  # Output: 5
Using int() function: The int() function can convert a floating-point number to an integer by truncating the decimal part: 
   x = int(4.7)

y = int(-3.9)


print(x)  # Output: 4


print(y)  # Output: -4
Using int() function with a base: The int() function can also convert strings to integers, using the specified base (0 for decimal, 8 for octal, or 16 for hexadecimal): 
   x = int('123', 10)  # Output: 123

y = int('ff', 16)  # Output: 255


z = int('1111', 2)  # Output: 15
Using long() function: The long() function is similar to the int() function but can handle larger integers: 
   x = long(2147483647)

y = long(-2147483648)


print(x)  # Output: 2147483647


print(y)  # Output: -2147483648
Using math.floor() function: The math.floor() function from the math module can round a floating-point number down to an integer: 
   import math

x = math.floor(4.7)


y = math.floor(-3.9)


print(x)  # Output: 4


print(y)  # Output: -4

Remember that Python 3 has changed some behavior related to integers compared to Python 2. For instance, division of two integers in Python 3 will result in a float, not an integer.

I hope this helps! Let me know if you have any further questions.

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