In this tutorial, we are going to discuss two main inbuilt functions in Python, namely print() and input(), that you often need to use in your code to perform I/O (Input/Output) operations. Also, we will discuss what the import keyword is and why we use it. So, without further ado, let's get started!
Python print(), input(), and import
In Python, you will get several inbuilt functions capable of performing specific tasks. In our previous Python tutorials, we have used the
print()
function a lot, and now, you might want to know how it work. Well, in the upcoming sections, we will explain the
print()
function which facilitates output operations in Python. Also, we will discuss the
input()
function which facilitates input operations.
Python print() Function
In Python, if you want to show something on-screen as an output, you can use the print() function. Usually, the
print()
function allows you to show the output data of variables and
strings
.
Let’s understand the
print()
function with an example:
print("to print a normal string you can use quotes, it could be single or double")
x=10
# to print a variable just put it inside the print function
#inside the print function if you do use the quotes it treats as a variable
print("x") #here x is a string
print(x) #here x is a variable containing a value 10
#use comma, to separate two different data types while using the print option
integer = 10
string = "Hello world"
print(string, integer)
Output
x
10
Hello world 10
If you write two print statements, you will get two outputs in two lines because the print() function has an additional keyword
inside it with
default value
'
\n'
,
which is used to print a new line. However, if you want, you can alter the value of the
end.
e.g.
print("Hello" , end="#" )
print("world")
print("hello", end="\t")
print("world")
Output
Hello#world
hello world
String Formatting:
There is a special function called
format()
which is used with a string. It gives you more flexibility over the
print()
function. The
format()
function is used with a string, and you can insert variables in specific places of that particular string. We use {} curly brackets to hold the places of variables or strings that pass in the format() function. Let’s try to understand the
format()
function with an example:
s= "Steve"
age=30
print("hi, there my name is {} and I am {} years old ". format(s,age))
#Output
hi, there my name is Steve and I am 30 years old.
The {} is also known as placeholders for the
format()
function, and the placeholders should correspond to the variables passed in the
format()
function. You can also use indexing in the placeholder to call the corresponding values in the
format()
function. e.g.
print("i love {1} and {0}".format("mangoes","apples"))
print("i love {0} and {0}".format("mangoes","apples"))
#Output
i love apples and mangoes
i love mangoes and mangoes
Python input() Function
In the above examples, we assign the values to the variable before we ran the program. However, what if we want to get a value from the user rather than pre-defining it? Well, we can use the input() function that allows a user to input the values in the program. Whenever you input a value in the program with the help of the input() function, the value is treated as a string. Remember that if you want to enter an integer or float, you need to use
type casting
.
input()
function syntax
variable = input([prompt])
Here whatever value we enter will store in the variable . The prompt is a string that is used as a message that displays on the screen
Let’s understand the
input()
function with an example:
input_1=input("Whatever you enter here treated as a string: ")
integer = int(input("Enter an integer: "))
float_1= float(input("Enter a float: "))
print(input_1)
print(integer)
print(float_1)
Output
Whatever you enter here treated as a string: 30
Enter an integer: 40
Enter a float: 50
30
40
50.0
Import in Python:
Import is a keyword that is used to import the definitions or functions from a module. Also, a module is a Python file that contains prewritten code or functions. The import keyword is used along with another keyword
from
which is used to import the module. Suppose you want
a program
that accepts an integer and give the square root of the integer. For this, you can make a program or you can use a predefined function
sqrt()
, which is a part of module
math
.
So, to use the
sqrt()
function, you must import it on your current file using the import keyword.
Let’s understand it with the following example:
from math import sqrt
var = int(input("Enter a Number: "))
sqt = sqrt(var)
print(sqt)
Output
Enter a Number: 10
3.1622776601683795
Important Points to Remember
- To print two data types using the print() function, use a comma to separate them.
- Use Type conversion to convert the data type of the value you get from the input() function.
- The from keyword is used to import a module.
- The import keyword imports the definitions or functions from a module.
- There are many modules in Python.
- You can also install third-party modules or libraries using the pip install command .
Conclusion
In Python, we can use
print()
and
input()
functions to perform input/output operations. As a Python developer, you need to be well aware of both functions because you may need to use them multiple times within a Python program.
Also, you need to understand the import keyword, which allows you to import and use the definitions and functions available within a module.