--- title: 2.2 Reading Input from the User description: Most programs are interactive, meaning they allow users to provide data while the program is running. Instead of using fixed values, a program can ask the user to enter information such as their name, age, salary, or marks. Python provides… url: "https://edcret.in/docs/python-programming/basic-refreshers-python/2-2-reading-input-from-the-user/" updated: "2026-07-29" category: Python Programming / Basic Refreshers --- # 2.2 Reading Input from the User Most programs are interactive, meaning they allow users to provide data while the program is running. Instead of using fixed values, a program can ask the user to enter information such as their name, age, salary, or marks. Python provides the built-in `input()` function to read data from the keyboard. The `input()` function always waits for the user to type something and press the **Enter** key. --- ## Syntax ``` input(prompt) ``` ### Parameter | Parameter | Description | | --- | --- | | `prompt` | An optional message displayed before waiting for user input. | ### Return Value The `input()` function always returns the entered value as a **string (`str`)**, regardless of what the user types. --- ## Example 1: Reading Input Without a Prompt **main.py** ``` name = input() print(name) ``` ### Sample Input ``` Alice ``` ### Output ``` Alice ``` ### Explanation - `input()` waits for the user to enter data. - The user types `Alice` and presses the **Enter** key. - The entered text is stored in the variable `name`. - `print(name)` displays the value stored in the variable. --- ## Example 2: Reading Input With a Prompt **main.py** ``` name = input("Enter your name: ") print("Welcome", name) ``` ### Sample Input ``` Enter your name: Alice ``` ### Output ``` Welcome Alice ``` ### Explanation - The string `"Enter your name: "` is displayed before waiting for input. - The user enters `Alice`. - The entered value is stored in the variable `name`. - The `print()` function displays a welcome message along with the entered name. --- ## Example 3: Reading an Integer **main.py** ``` age = int(input("Enter your age: ")) print(age) ``` ### Sample Input ``` Enter your age: 25 ``` ### Output ``` 25 ``` ### Explanation - `input()` always returns a string. - The `int()` function converts the string into an integer. - The converted value is stored in the variable `age`. - Since `age` is now an integer, it can be used for mathematical calculations. --- ## Example 4: Reading a Floating-Point Number **main.py** ``` salary = float(input("Enter your salary: ")) print(salary) ``` ### Sample Input ``` Enter your salary: 35000.75 ``` ### Output ``` 35000.75 ``` ### Explanation - `float()` converts the entered string into a floating-point number. - Floating-point numbers are used to represent values containing a decimal point. - The converted value is stored in the variable `salary`. --- ## Example 5: Reading Multiple Values **main.py** ``` first_name, last_name = input("Enter your full name: ").split() print(first_name) print(last_name) ``` ### Sample Input ``` Enter your full name: John Smith ``` ### Output ``` John Smith ``` ### Explanation - `input()` reads the entire line entered by the user. - `.split()` divides the string into separate parts using spaces. - The first word is assigned to `first_name`. - The second word is assigned to `last_name`. --- ## Example 6: Reading Multiple Integers **main.py** ``` a, b = map(int, input("Enter two numbers: ").split()) print(a) print(b) ``` ### Sample Input ``` Enter two numbers: 10 20 ``` ### Output ``` 10 20 ``` ### Explanation - `input()` reads the entire line. - `.split()` separates the values based on spaces. - `map(int, ...)` converts every value into an integer. - The converted integers are assigned to `a` and `b`. --- ## Example 7: Reading a List of Integers **main.py** ``` numbers = list(map(int, input("Enter numbers: ").split())) print(numbers) ``` ### Sample Input ``` Enter numbers: 10 20 30 40 50 ``` ### Output ``` [10, 20, 30, 40, 50] ``` ### Explanation - The user enters multiple numbers separated by spaces. - `.split()` converts the input into a list of strings. - `map(int, ...)` converts each string into an integer. - `list()` converts the result into a Python list. --- ## Example 8: Reading a Sentence **main.py** ``` sentence = input("Enter a sentence: ") print(sentence) ``` ### Sample Input ``` Enter a sentence: Python is easy to learn. ``` ### Output ``` Python is easy to learn. ``` ### Explanation - `input()` reads the complete line entered by the user. - Spaces are preserved. - The entire sentence is stored as a single string. --- ## Example 9: Reading a Single Character **main.py** ``` ch = input("Enter a character: ")[0] print(ch) ``` ### Sample Input ``` Enter a character: Apple ``` ### Output ``` A ``` ### Explanation - `input()` reads the complete string entered by the user. - `[0]` accesses the first character of the string. - Even if multiple characters are entered, only the first one is stored. --- ## Example 10: Verifying the Return Type of `input()` **main.py** ``` value = input("Enter any value: ") print(type(value)) ``` ### Sample Input ``` Enter any value: 100 ``` ### Output ``` ``` ### Explanation - Even though the user entered a number, `input()` returns a string. - The `type()` function displays the data type of a variable. - This is why type conversion using `int()` or `float()` is often required. --- # Common Mistakes ### 1. Assuming `input()` Returns an Integer **Incorrect** ``` age = input("Enter your age: ") print(age + 5) ``` ### Sample Input ``` 25 ``` ### Output ``` TypeError: can only concatenate str (not "int") to str ``` **Reason** `input()` returns a string, so Python cannot add an integer to it. **Correct** ``` age = int(input("Enter your age: ")) print(age + 5) ``` --- ### 2. Forgetting to Use `.split()` **Incorrect** ``` a, b = input() ``` ### Sample Input ``` 10 20 ``` ### Output ``` ValueError: too many values to unpack ``` **Reason** Without `.split()`, the entire input is treated as one string instead of two separate values. **Correct** ``` a, b = input().split() ``` --- ### 3. Entering Non-Numeric Data for `int()` **Incorrect Input** ``` age = int(input("Enter age: ")) ``` ### Sample Input ``` abc ``` ### Output ``` ValueError: invalid literal for int() with base 10: 'abc' ``` **Reason** The entered text cannot be converted into an integer. --- ### 4. Accessing the First Character of an Empty String **Incorrect** ``` ch = input()[0] ``` ### Sample Input (User presses **Enter** without typing anything.) ### Output ``` IndexError: string index out of range ``` **Reason** The input string is empty, so there is no first character. --- # Key Points to Remember - `input()` is the built-in function used to read keyboard input. - The prompt parameter is optional. - `input()` always returns a **string**. - Use `int()` to convert input into an integer. - Use `float()` to convert input into a floating-point number. - Use `.split()` to read multiple values from one line. - Use `map()` to convert multiple input values into another data type. - A single character can be obtained using string indexing. - Always validate user input in real-world applications.