User Input in Python with Examples [A Complete Guide] (2024)

In Python programming, interacting with users is a key part of collecting data and showcasing results. Here, we'll explore the ins and outs of user input, a vital aspect for developers. Python offers integrated features like the input() method in the latest version and raw_input() in earlier ones. If you're looking to enhance your Python programming skills, understanding user input is essential, and this knowledge can be gained through Python Programming training. I'll guide you through the syntax, examples, and practical uses of these functions, highlighting how they help developers effortlessly communicate with users. Together, we'll unravel the simplicity and effectiveness of Python user input, empowering you to enhance the interactivity of your Python applications. Let's dive into the world of Python user input!

Asdevelopers, weneed to communicate with users to collect data or togenerateresults. Many applications today usedifferent waysto request a certain form of input from the user. Python offers us integrated features to take the input. The latest version of Python uses theinput() method while the earlier version uses theraw_input() method.

To do this, wehave toclick the Enter button after entering the value from the keyboard. The input() function then reads the user’s value. The input function reads a line from the console,then converts it to a string, and returns it.To read about Self in Python, click here!

What are User Inputs in Python?

In Python programming, understanding user input is fundamental for developers aiming to create interactive applications.Here'sa breakdown of what user inputs entail:

1. Purpose:User inputs allow developers to collect data or obtain specific information from users, fostering interaction and customization within Python applications.
2. Input Methods:Python provides integrated features for capturing user inputs. The input() method, predominant in the latest Python version, and the older raw_input() method serve as mechanisms to gather information.
3. Syntax:The syntax of the input() function is straightforward – input(prompt). The prompt string guides users, indicating the type of input expected and enhancing the user experience.
4. Data Conversion:The input() function treats all input as strings. To work with numerical values, developers can use conversion functions like int() or float() to ensure the correct data type.
5. Handling Different Data Types:Python user input covers a spectrum of data types. Whether capturing strings, integers, or floats, developers can tailor their approach based on the specific requirements of the application.
6. Error Handling:Python addresses potential errors, such as EOFError, that may occur during the input process. Handling these exceptions ensures a smooth user experience and prevents unexpected disruptions.
7. Applications:User inputs play a crucial role in a variety of applications, from simple data entry tasks to more complex scenarios like decision-making based on user choices.

Bycomprehendinguser inputs in Python, developers gain the ability to createapplications that are not only functional but also user-friendly and adaptable to diverse input scenarios. This understanding forms the basis for building dynamic and engaging Python programs that cater to the unique needs of individual users.

Syntax of input() Function

The syntax of input() function is:

input(prompt)

In the console, the prompt string isprinted,and the user is given the command to enter the value. You should print some useful information to help the user enter the expected value.

Getting User Input in Python

Theinput() function receives the user input from the keyboard and stores it into a variable name. Here str is a variableand theprint() function prints it to the screen.

Theinput() function delays the execution of a program to allow the user to type the input from the keyboard. On pressing Enter, all characters are reads and returned as a string.

String input from the user:

Example:

Here is an example of getting the user input and printing it on the console.

str = input(“Enter your name: “)print(str)

Output:

Enter your name: JosephJoseph

Float Input from user:

Wewilluse float() function to convert the received input into a float value.

Example:

value = float(input("Enter a value: "))print(value)

Output:

Enter a value:200.99200.99

How to Get an Integer as the User Input?

The input function convertswhatever you enter as an inputinto a string. If you enter an integer value, theinput() function will convert it to a string.

To use theintegers,we can use the built-in functions to convert it into an int.

Example:

value =input("Enter an integer:\n")value =int(value)print(f'Theentered number is {value} and its square is {value ** 2}')

Output:

Enter an integer:10The entered number is 10 and its square is 100

Example:

# take multiple inputs in arrayinput_str_array= input().split()print("array:",input_str_array)# take multiple inputs in arrayinput_int_array= [ int(x) for x in input().split()]print("array:",input_int_array)

Output:

10 20 30 40 50 60 70array: ['10', '20', '30', '40', '50', '60', '70']10 20 30 40 50 60 70array: [10, 20, 30, 40, 50, 60, 70]

Python user input and EOFError Example:

EOFErrorinPythonis one of theexceptions to handleerrorsand is raised in scenarios such as the interruption of theinput() function in both Python version 2.7 and Python version 3.6, as well asother versions after version 3.6 or when theinput() function reaches the unexpected end of the file in python version 2.7,i.e.the functions do not read any databefore the end of the input is encountered.

Methods such asread() must return a string that is empty at the end of the file, which is inherited in Python from the exception class that is inherited inBase Exceptionclass. This mistake often happens with online IDEs.

If the input() function did not read anydatathen the Python code will throw an exceptioni.e.EOFError.

value =input("Please enter an integer:\n")print(f'Youentered {value}')

Output:

Enter a value: Traceback (most recent call last):File “example.py”, line 1, in <module>value =input(“Please enter an integer: “)EOFError

Working of EOFError in Python

1. The BaseException class inherits the EOFError class as the base class of the Exception class.
2. EOFErrortechnically is not an error, but an exception. When the built-in functions, such as theinput() function orread() function return a string that is empty without reading any data, theEOFErrorexception is raised.
3. This exception is raised if our software tries to retrieve anything and make changes to it, but if no data is read and a string is returned, the EOFError exception is raised.

Steps to Avoid EOFError in Python

If End of file Error or EOFError occurs, the exception EOFError is raised without reading any information by theinput() function. We should try to enter something like CTRL + Z or CTRL + D before submitting the End-of-file exception to prevent the raising of this exception.

Example:

try:data =raw_input("Do you want tocontinue?:")exceptEOFError:print ("Error: No input or EndOfFile is reached!")data = ""print data

Output:

Theinput provided by the user is being read which is: Hello this is demonstration of EOFError Exception in Python.The input provided by the user is being read which is: EOF when reading a line. 

Explanation:In the above program, try to prevent theEOFErrorexception with an empty string, which doesn't print the error message of the EndOfFile and rather prints the personalized message that is shown in the program and prints the same on the output. 

You can use the try and catch block if the exception EOFError isprocessed.

Python User Input Choice Example

Python provides a multiple-choice input system. Youhave tofirst get the keyboard input by calling the input() function. Then evaluate the choice by using the if-elif-else structure.

value1 = input("Please enter first integer:\n")value2 = input("Please enter second integer:\n") v1 = int(value1)v2 = int(value2) choice = input("Enter 1 for addition.\nEnter2 for subtraction.\nEnter3 for Multiplication:\n")choice = int(choice) if choice == 1:print(f'Youentered {v1} and {v2} and their addition is {v1 + v2}')elif choice == 2:print(f'Youentered {v1} and {v2} and their subtraction is {v1 - v2}')elif choice == 3:print(f'Youentered {v1} and {v2} and their multiplication is {v1 * v2}')else:print("Wrong Choice, terminating the program.")

Output:

Please enter first integer:20Please enter second integer:10Enter 1 for addition.Enter 2 for subtraction.Enter 3 for Multiplication:2You entered 20 and 10 and their subtraction is 10

Python raw_input() function

Python raw_input function is a built-in function used to get the values from the user. This function is used only in the older versions of Python i.e. Python 2.x version.

• Two functions are available in Python 2.x to take the user value. The first is the input function and the second is the raw_input() function.
• Theraw_inputfunction in Python 2.x is recommended for developers.This is because the input function is vulnerable in version 2.x of Python.

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Python 2.x environment setup:

Python 2 must be installed in your systemin order touse the rawinput() function .Use python2 instead of python or Python3 if you run your program from a terminal. Therefore, the execution sample command is:

$python2 example.py

It depends on how yourpython have installed. In conclusion, you mustrun your Python programusing the version python 2.x if you use theraw_inputfunction.

You can modify your Python compiler if you use PyCharm IDE. Go to File-> Configuration -> Project -> Project Interpreter for that purpose. Then select Python 2.x from the list.

Example1:

We will see a code written in Python 2.x version.

name = raw_input(‘Enter your name : ‘)print ‘Username :‘, name

Output:

Enter your name : SteveUsername :Steve

Example 2:

# input() function in Python2.xvalue1 =raw_input("Enter the name: ")print(type(value1))print(value1)value2 =raw_input("Enter the number: ")print(type(value2))value2 = int(value2)print(type(value2))print(value2)

Output:

Enter the name: Jenny<type ‘str’> Jenny Enter the number: ‘9876’ <type ‘str’> <type ‘int’> 9876

The "Jenny" value is taken from the user in the value1 variable here and stored in the value1. The string for raw input function is always the type of value stored. The value“9876”istaken from the user and stored in the variable value2. The variable value2 type is a string now and the typeneeds to be converted to an integer withint(). The value2 variable saves an integer type for the value "9876."

The function rawinput() was deactivated and removed from Python 3.You can update now ifyou'restill on a Python 2.x.

Conclusion

In Python, I rely on a basic framework for Python user input. The input function serves as my go-to tool, reading and transforming a line from the console into a string. It automatically converts all input into a string format, and when I need to adjust the format, I simply use a conversion type.

Its primary purpose in my programmingendeavorsis to offer users options and dynamically alter the program flow based on their input.I'venoticed that the software patiently awaits the user's input indefinitely, which is great, but having a timeout and default value would be handy if users take their time.

I've come across EOFError, which is technically not an error but an exception, especially important to understand duringPython Programming training. This occurs when functions like input() or read() return an open string without reading any data, triggering the EOFError exception. It's a nuanced aspect of user input handling that I've encountered in my Python programming experiences.