Python Data Types

Python Data Types

A data type is a classification of one of a variety of types of data, such as Number, Boolean, Strings and so on. Data types determine the possible value for the type. If an operation is done then it can be done on the value of that type.

In the Python programming language  every values has a datatype. You don't need to declare it but you don't need to declare the datatype for that specific variable. Like in JavaScript based on the data that we assign to the variable, Python determines the type. In the Python everything is an object.

 

Python has many  native datatypes that are listed as in the following:

• Boolean: Ture or False
• Integer: Positive and Negative values like -1,-2, 0, 2, 8 and so on.
• Float: 0.2, 2.8 and so on.
• Fraction: 3/5, 2/7 and so on.
• Complex: Values that have real part and complex part like 2 + 3i.
• String: String are the sequence of Unicode characters
• Byte and Byte Array: This data type can save any binary files like Image(jpg, png, bmp and so on. )
• List: Ordered sequence of value.
• Tuples: Ordered immutable sequence of value.
• Sets: Unordered bag of values.
• Dictionaries: Unordered bags of key-value pair.

Boolean: Booleans are either true or false. There are two constants, True and False, that can be used to assign value directly. Python expects an expression to evaluate to a boolean value. These places are called boolean contexts. We can write any expression in boolean contexts.

Example 1

a=True;
print(a);

Output

True

 

In Python booleans can be treated as numbers. A True value is 1 and a False value is 0. You can also do any operation between boolean values in Python.

 

Example 2

a=True
b=True
print(a+b)

Output

2

Because Python treats a true value as 1 and a false value as 0. Here a and  b both are true so 1 + 1 = 2.

Example 3

a=False
b=True
print(a-b)

Output

-1

Example 4

a=True
b=False
print(a * b)

Output

0

Example 5

a=True
b=False
print(a / b)

Output

 

Integer

An Integer type holds an integer value or a whole number that can be a negative or positive value, like -5, -4, 0, 8, 9, 10 and so on. In the Python you can declare an integer value such as in the following:

a=12;
print(a);

Output

12

But in the preceding example you cannot determine the type of the a Variable. So in Python we have a function by which we can get the type of a variable. The function is as in the following:

type(variable)

Example

a=12
print(type(a))

Output

 

 

We can represent any integer variable in Decimal or Octal or Hexa-Decimal format.

in Decimal

In decimal you can write directly your Python variable as in the following:

a=12

in Octal

In Octal you can represent such as in the following:

a=0O14

or

a=0o14

Example

a=0O14
print(a)

Output

 

In Hexa-Decimal: You can represent any integer variable as a Hexa-decimal such as in the following:

a=0XC

or

a=0xC

Example

a=0xC
print(a)

Output

 

 

Float

Float values are values that contain decimal points or a value that contains an exponent and mantissa.

Example

PI=3.14
print("Type of PI is: \n")
print(type(PI)) #This will print type of PI

print("\n\nValue of PI is : %f" %PI)

Output

 

 

We can also represent a floating point number in E notation.

Example

a=1.5E+2
electron_charge=1.602E-19
speed_of_light=3.0E+8

print(a);
print(electron_charge)
print(speed_of_light)

Output

 

 

Fraction

In Python you can also create a type that can hold fractional numbers, like 1/2, 3/5 and so on. To create a Fractional type of number you must import the "fractions" module. Than you need to create a Fraction object.

Example 

import fractions
x = fractions.Fraction(1, 3)
print(x)

 Output

 

 

Not only that, you can also operate fractional numbers.

Example

import fractions
x = fractions.Fraction(1, 5)
y = fractions.Fraction(2, 5)
print("%s + %s = %s"%(x,y,(x+y)))

 Output

 

 

"Fraction objects are automatically reduced to fractions": Assume we have a number (6/12) then it will becomes (1/2).

Example

import fractions
x = fractions.Fraction(6, 12)
print(x)

 Output

  

 

"Note: You can not create a fraction with a zero denominator like 5/0 or 0/0"

Complex Type

In Python you can create a Complex type variable that will have a real part as well as an imaginary part, like 3 + 5i. Here the real part is 3 and the imaginary part is 5.

To create the complex type of variable in Python we have a function called complex(real_part, imaginary_part) that takes two arguments, a real part and an imaginary part.

Example

x = complex(3,5)
print(x)

Output

 

 

You can also perform any operation on this, like:

x = complex(3,5)
y = complex(5,6)
print("%s + %s = %s"%(x,y,(x+y)))

Output: (3+5j) + (5+6j) = (8+11j)

String Type: the String datatype is the same as in other languages.

Example

x="Hello C-Sharp Corner!"
print(x)

Output

 

 

Byte and Byte Array

These objects can store binary buffers. The length of a Byte type is 1 byte, which is 8 bits. So its range will be 0 to 255. It means bytes can efficiently be one byte of data. A byte array is the type that can hold more than one byte. As we have discussed, a byte can hold the binary data so we can store any binary file in a byte array, like image, songs and so on.

We can create any bytearray and byte variable such as in the following:

SomeData= [0, 200, 50, 25, 10, 255]

values = bytearray(elements)#creating Byte array

data = bytes(elements)#creating Byte data.

In the bytearray we can modify the values as in:

values[0]=4
values[1]=10

But in the byte type we cannot modify the value.

data[2]=10 # This cannot be possible because Byte does not support item assignment.

Lists Data Type: Lists are ordered sequences of values. 

Creating a list: Creating a list is very easy, you can create a Python list using square brackets and wrap comma-separated list items in square brackets. 

Example

list=['C','C++','Java','C#']
print(list)

Output

 

You can also print the individual items of the list with its index like an array.

Example

list=['C','C++','Java','C#']
print(list[3])

The preceding example will print "C#".

 

Slicing the list: Once you have created a list you can slice that list, in other words you can get any part of the list.

Example 1

list=['C','C++','Java','C#','Python']
print(list[1:4])

Output 

 

 

Example 2

list=['C','C++','Java','C#','Python']
print(list[3:])# it will print : ['C#', 'Python']
print(list[:3]) # it will print : ['C', 'C++', 'Java']

Output

 

 

Lists are mutable: we can modify the list items after we created the list.

Example

list=['C','C++','Java','C#','Python']
list[3]='HTML'  #we can modify list item
print(list[3])

Output

HTML

 

Tuples Type

A tuple is the same as a list but the difference is that a tuple is "immutable", in other words we cannot modify a tuple after creating it.

How to create: Tuple is created the same as a list but it is enclosed in parenthesis.

Example

tuple=('C','C++','Java','C#','Python')
print(tuple[3])
tuple[3]='HTML'# this is not possible because tuple is immutable

Output

 

 

Sets: A set is a well-defined collection of distinct objects. This is also an immutable type. Once you have created a set you can perform set operations like union, intersection, and so on.

A set can be defined the same as a list but they are enclosed in curly braces ({}).

Example

number_set={1,2,3,4,5,6,7,8,9}
print(number_set)

Dictionaries

This is an unordered set of values that has two parts, the key and a value. In other words a Dictionary contains key-value pairs for fast lookup of the data. We can access our data faster using a Dictionary.

Example

Person={'First_Name':'Sourabh','Last_Name':'Somani','Website':'http://www.sourabhsomani.com/'}
print(Person)
print(Person['First_Name'])
print(Person['Last_Name'])
print(Person['Website'])

I hope you like this. Thanks.