python input integer with code examples

In Python, the input() function is used to get input from the user. By default, the input is considered a string. However, sometimes we need to get input as an integer. In this article, we will discuss various ways to input integers in Python with code examples.

Method 1: Using int() function

The int() function is used to convert a string to an integer. We can use this function to convert the input obtained from the input() function to an integer. Here's an example:

num = int(input("Enter a number: "))
print("The number entered is: ", num)

Output:

Enter a number: 25
The number entered is:  25

Method 2: Using eval() function

The eval() function is used to evaluate an expression. We can use this function to evaluate the input obtained from the input() function as an integer. Here's an example:

num = eval(input("Enter a number: "))
print("The number entered is: ", num)

Output:

Enter a number: 25
The number entered is:  25

Method 3: Using str.isdigit() method

The str.isdigit() method is used to check if a string contains only digits. We can use this method to check if the input obtained from the input() function is a valid integer. Here's an example:

num = input("Enter a number: ")
if num.isdigit():
    num = int(num)
    print("The number entered is: ", num)
else:
    print("Invalid input")

Output:

Enter a number: 25
The number entered is:  25

In this way, we can input integers in Python using various methods like int(), eval(), str.isdigit(). It's important to use str.isdigit() method for checking the input is valid or not before converting it to int to avoid any unwanted errors or exceptions.

Method 4: Using float() function

The float() function is used to convert a string to a floating-point number. We can use this function to convert the input obtained from the input() function to a float. Here's an example:

num = float(input("Enter a number: "))
print("The number entered is: ", num)

Output:

Enter a number: 25.5
The number entered is:  25.5

Method 5: Using str.replace() method

The str.replace() method is used to replace a specific substring with another substring in a string. We can use this method to remove any unwanted characters from the input obtained from the input() function. Here's an example:

num = input("Enter a number: ")
num = num.replace(',', '') # remove any commas
num = int(num)
print("The number entered is: ", num)

Output:

Enter a number: 25,000
The number entered is:  25000

Method 6: Using try-except block

A try-except block is used to handle exceptions in Python. We can use this block to handle any exceptions that may occur while converting the input obtained from the input() function to an integer. Here's an example:

while True:
    try:
        num = int(input("Enter a number: "))
        break
    except ValueError:
        print("Invalid input. Please enter a valid number.")
print("The number entered is: ", num)

Output:

Enter a number: 25
The number entered is:  25

In this way, we can input integers and float in python using various methods. It's good to have knowledge of different ways of inputting integers and floats as it can come in handy in different situations. Also, the try-except block is very useful as it can handle any exceptions that may occur while inputting integers and floats.

Popular questions

1. How can we input an integer in Python using the input() function?

• We can use the int() function to convert the input obtained from the input() function to an integer. For example: num = int(input("Enter a number: "))

2. What is the use of the eval() function in inputting integers in Python?

• The eval() function is used to evaluate an expression. We can use this function to evaluate the input obtained from the input() function as an integer. For example: num = eval(input("Enter a number: "))

3. What is the use of the str.isdigit() method in inputting integers in Python?

• The str.isdigit() method is used to check if a string contains only digits. We can use this method to check if the input obtained from the input() function is a valid integer.

4. How can we input a float in Python using the input() function?

• We can use the float() function to convert the input obtained from the input() function to a float. For example: num = float(input("Enter a number: "))

5. How can we handle exceptions while inputting integers in Python using the try-except block?

• A try-except block is used to handle exceptions in Python. We can use this block to handle any exceptions that may occur while converting the input obtained from the input() function to an integer. For example:

while True:
    try:
        num = int(input("Enter a number: "))
        break
    except ValueError:
        print("Invalid input. Please enter a valid number.")

Tag

Inputting