11.1.1.1 organize data output
11.1.1.2 use the escape sequences with data output

Output data / Вывод данных

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print(arguments) - function for output data on display.

Task. Output text "Hello, world!" on display:

print("Hello, world!")

Output data:

Hello, world!

Wing IDE

Who is the best programmer?

print("Hi!")
print("I am the best programmer!")

Output data:

Hi!
I am the best programmer!

Function print can have more than one argument:

print(arg1, arg2, arg3, …)

Arguments can be:

• Strings: “Hello”, “course of Python”, “” , … 
• Variables: a, name, number5, …
• Math expressions: 4 * a, 20 / 7, …

Who is the best programmer? (use only one print)

print("Hi!\nI am the best programmer!")

Output data:

Hi! 
I am the best programmer!

Escape sequences

Using escape sequences.

Example

print("text1\ntext2")

Display:

text1
text2

Example

print("Carrot\t250 tenge\nBetroot\t280 tenge")

Display:

Carrot      250 tenge
Betroot     280 tenge
 

Define the result of the next code

print("\u1D66")

Argument sep (separator) 

Program:

print("2", "+", "2", "=", "4", sep="")

Display:

2+2=4

Program:

print("a", "b", "c", "d", "e", sep="-")

Display:

a-b-c-d-e

Argument end

What will output at the end of print

Program:

print("1", end="") 
print("23", end="-") 
print("456") 

Display:

123-456

Variables

A variable is an identifier that can change the stored value during the execution of the program.

hello = 'Hi'
hello2 = hello
print(hello2)

Rules for creating variables in Python

• Variable names must start with a letter or underscore.
• Variable names cannot start with a digit.
• A variable name can only contain letters, digits, and underscores (A - z, 0-9, and _).
• Variable names are case sensitive (num, Num, and NUM are three different variables).
• Don't use reserved words (keywords) as a variable name.

number = 10      # variable number of integer type assigns the value 10
pi = 3.14        # floating point pi is assigned the value 3.14
word = "Hello"   # variable word of string type assigns the value "Hello"
print(number, pi, word)

Variable can change the value in a program. 

word = "Astana"
print("2017 - ", word)
print("2018 –", word)
word = "Nur-Sultan"
print("2019 –", word)

Output data:

2017 - Astana
2018 - Astana
2019 – Nur-Sultan

Comments:

The comment starts with a hash character (#), and is followed by text that contains further explanations.

Example:

# defining the post code
postCode = 090014

If we want to comment out several lines at once, then use """.

Example:

"""comments
comments
comments"""

Questions:

1. How to output data in a Python program?

2. Explain what is variable.

3. Describe rules for variable's name.

4. How can you use comments in the program?

Exercises:

Ex.1

Tasks:

Tasks on Stepik.org course "Python Programming for NIS"