Python Console Input & Output Tutorial
In this tutorial we learn how to use Python's input() function to take values from the console, and the print() function to display data in the console.
How to output to the console with the print() function
The print() function contains all the functionality needed to output text to the console.
When the interpreter encounters the print statement, it will try to print everything we write between the ( ) (parentheses) to the console.
note Even though we haven’t covered functions and function calls yet, we’ll be using print so much that it’s important to learn about it early on.
How to print() text and numbers
To print text we wrap a word or sentence inside a pair of single or double quotes and pass it as an argument to the print function between the parentheses.
print('Hello World') print("Hello there")
Single characters form what’s known as a string. They are always be wrapped in single or double quotes.
Other values, like numbers, aren’t wrapped in quotes.
How to do arithmetic and print the result
We can do arithmetic directly inside the argument list of the print function. The interpreter will calculate the result before printing it to the console.
print(1 + 2) print(9 - 5) print(3 * 4) print(6 / 2)
How to combine (concatenate) letters and numbers
Concatenation is when we combine multiple strings, or numbers and strings, to form a larger string.
In Python there are multiple ways to concatenate strings and numbers. For the print function, we can simply separate our strings and numbers with a comma operator and it will combine them.
print("The answer to the ultimate question of life is, ", 42)
When concatenating strings and numbers, we have to separate the strings and numbers in the order we want to combine them.
print("If you had", 1, "shot, or", 1, "opportunity, to seize...")
In the examples above, the interpreter converts the numbers into strings and inserts them into the chosen positions in the string.
note We cannot perform arithmetic with numbers that are already converted into strings.
How to print data containers
We can store data inside a data container, like a variable, and then print the variable. The print function will then try to print the contents of the data container.
note Don’t worry if you don’t understand variables yet, we will cover them in the next lesson.
msg = "Hello World" print(msg)
We use the name of our data container, “msg” in this case, as the argument for the print function.
We could do the same with more complex data containers like lists.
shopping = ["Bread", "Milk"] print(shopping)
How to take input from the console with the input function
We can use the input() function to take data in from the console. It will read the keystrokes as a string object and can be stored into a data container.
input("Please enter your name: ")
You will be able to click inside the console and type some text. The argument we specified between the parentheses of the output() function is simply the text we see in the console before it asks us for input.
note If you are working in PyCharm the console will show in the Run tab. You can interact with it there.
Right now we’ve received input, but we’re not storing or using it in any way. We can store it into a data container such as a variable and then print the input received.
# store input into data container x x = input("Please enter your name: ") # print the data container's value print("Welcome", x)
If we run the example above, it will ask us to enter a name. Once we enter a name, and hit Enter on the keyboard, it will display the welcome message we set up in the print statement.
Basically, whatever we type will replace the x in the code above.
Summary: Points to remember
- We can use the
function to receive input from the console.
- We can store the input into a data container to easily work with the data.
- We can use the
function to output text to the console.
- When we output text, we have to wrap the words or sentences in either single or double quotes.
- We can do arithmetic directly inside the function’s parentheses.
- Numbers do not need to be wrapped inside quotes.
- A simple and easy way to concatenate our text and numbers is by separating them with commas between the function’s parentheses.
- We can store data in data containers (like variables) and use them to output the stored values.