Python, like any other programming language, supports multiple datatypes. In this lesson, we'll review the most common datatypes used in Python.

Integers

Python has integers.

print(1 + 2)

We can do the usual arthemetic operators +, -, * and /.

print(7 + 2)
print(7 - 2)
print(7 * 2)
print(7 / 2)

There is a special operator // is used for integer division.

print(7 // 2)

And the ** operator is used to exponentiation or to raise a number to a power.

print(2 ** 10)

It is fun to play with large numbers in Python.

print(2 ** 1000)

Floating Point Numbers

Python has floating point numbers. All operators that work on integers work on float point numbers too.

print(0.1 + 0.2)

You may be surprised why the answer is not 0.3. That is a do with how the number of represented internally. We are not going into those details for now, you can google for 0.1 + 0.2 to find more about it.

Strings

Python has string to represent text. Strings are enclosed in single quotes or double quotes.

name = 'Python'
print('Hello', name)

We can use the + operator to concatinate two strings.

x = 'hello' + 'python'
print(x)

The * operator can be used to repeat a string multiple times.

print('hello' * 4)
print('=' * 20)

The built-in function len can be used to find the length of a string.

name = 'Python'
print(len(name))

Python supports writing multi-line strings. They are enclosed in three single quotes of three double-quotes. They are typically used to write multi-line messages that we want to print or send an email etc.

message = '''
Hello everyone,

Welcome to the Python Primer course!
'''

print(message)

Python supports the usual escape codes. The new line character is represented as \n and the tab character is represented as \t.

print('a\nb\nc')
print('1\t2\t3')

The strings also support unicode strings. The following example demonstrates strings written in multiple Indian languages.

print('అ ఆ ఇ ఈ') # Telugu
print('ಅ ಆ ಇ ಈ') # Kannada
print('அ ஆ இ ஈ') # Tamil
print('അ ആ ഇ ഈ') # Malayalam
print('अ आ इ ई') # Hindi

The unicode characters can also be written using their unicode code points.

print('\u0c05 \u0c06 \u0c07 \u0c08') # Telugu
print('\u0c85 \u0c86 \u0c87 \u0c88') # Kannada
print('\u0b85 \u0b86 \u0b87 \u0b88') # Tamil
print('\u0d05 \u0d06 \u0d07 \u0d08') # Malayalam
print('\u0905 \u0906 \u0907 \u0908') # Hindi

Bytes

Python has a bytes datatype to represent binary data.

The bytes are written just like strings, but with b prefix.

data = b'abcd \x01\x02\x03\x04'
print(data)

In the above example, the letter a corresponds to a byte with value 97, which is the ascii code of the letter a. The \x01 is presents byte with value 1, written as two-digit hexadecimal number using prefix \x.

We'll learn more about bytes in the later lessons.

Lists

Python has a lists to represent a collection of values.

x = ['a', 'b', 'c']
print(x)

A list can contain values of different types, including other lists.

x = ['a', 'b', 1, 2, ['p', 10]]
print(x)

Individual elements of a list can be accessed by indexing it using the [] operator. The index starts with 0.

x = ['a', 'b', 'c']
print(x[0]) # the first element is at index 0
print(x[1]) # the second element is at index 1
print(x[2]) # the third element is at index 2

The built-in function len is used to find the length of a list.

x = ['a', 'b', 'c']
print(len(x))

Dictionaries

Dictionaries are used to represent name-value pairs. The dictionaries are very hand datastrcutures in Python and learning to use them effectively is a great asset.

person = {
    'name': 'Alice',
    'email': 'alice@example.com',
    'phone': '1234',
    'verified': True
}

print(person)
print(person['email'])

The values in a dictionary can be accessed using the key. In the previous example, we've printed the value of entry associated with the key email.

We'll learn more about dictionaries in the latter chapters.

Boolean Values

Python has boolean values too. The keywords True and False represent the boolean truth and false.

print(True)
print(False)

The conditional expressions are evalued to boolean values.

filesize = 100
print(filesize > 50)
print(filesize > 200)

Other Datatypes

Python have some other interesting datatypes as well.

The None is special value use to indicate nothing.

Python has another datatype called tuple for representing fixed width records. Tuples behave just like lists, but they are immutable.

point = (2, 3)
print(point)
print(point[0], point[1])

Python allows multiple-assignment also and it is handly to unpack tuples.

point = (2, 3)
x, y = point
print(x, y)

When writing tuples, the parenthesis can be omitted most of the times.

point = 2, 3
print(point)
print(point[0], point[1])

Python has a set datatype too. A set is an unordered collection of elements.

x = {1, 2, 3}
print(x)

Summary

In this lesson, we've seen various commonly used datatypes of Python. While they look very simple, mastering them takes a bit of practice. Make sure you go through all the examples and the practice problems in the subsequent lessons.