Reading and Writing: Writing

Writing with print

As we have seen before, print is the Python writing instruction and is used to write data to stdout.

To write a value, just pass the value as a parameter to print:

>>> print('Hello')
Hello
>>> print(2023)
2023
>>> var = 3.1416
>>> print(var)
3.1416

By default, print adds a newline at the end of the writing.

If you want to write many data items on a single line, you can pass multiple parameters separated by commas:

>>> print('Hello', 'Jordi')
Hello Jordi
>>> print(31, 12, 2023)
31 12 2023
>>> print()

>>> print(2023, 'Carles', 0.5)
2023 Carles 0.5

Without any parameter, it writes a blank line.

You can modify the behavior of print by specifying two additional parameters:

1. sep indicates what text will separate the given elements,

2. end indicates what text will be written at the end of the print.

By default, sep is a space and end is a newline.

These examples show how to use sep:

>>> print('Hello', 'Jordi', sep='_')
Hello_Jordi
>>> print(31, 12, 2023, sep='_')
31_12_2023
>>> print(31, 12, 2023, sep='')
31122023
>>> print(31, 12, 2023, sep='   ')
31   12   2023

And these examples show how to use end:

>>> print('Hello', 'Jordi', end='.')
Hello Jordi.>>> print('Hello', 'Jordi', end='\n\n')
Hello Jordi

>>>

In the first case, since instead of a newline a period was written, the prompt sticks to the text. In the second case, end is two newlines (the special text \n is a newline), so the writing leaves a blank line of separation.

Obviously, end and sep can be used together. This example separates the elements with commas and ends with a period:

>>> print('Amalia', 'Maria', 'Emma', end=',', sep='.')
Amalia,Maria,Emma.>>>

The prompt (>>>) is only visible because these examples use the Python interpreter. Rest assured that when we write complete programs, it will not appear.

print has more options, but these are the few that we will need.