Standard Data Types in python

Python has five standard data types-
1. Numbers
2. String
3. List
4. Tuple
5. Dictionary

1.Python Numbers
Number data types store numeric values. Number objects are created when you assign a value to them. For example-
var1 = 1
var2 = 10

You can also delete the reference to a number object by using the del statement. The syntax of the del statement is −

del var1[,var2[,var3[....,varN]]]]

You can delete a single object or multiple objects by using the del statement.
For example-
del var1

Python supports three different numerical types −
1. int (signed integers)
2. float (floating point real values)
3. complex (complex numbers)

2.Python Strings
Strings in Python are identified as a contiguous set of characters represented in the quotation marks.

#!/usr/bin/python3
str = 'Hello World!'
print (str)                  # Prints complete string
print (str[0])              # Prints first character of the string
print (str[2:5])           # Prints characters starting from 3rd to 5th
print (str[2:])             # Prints string starting from 3rd character
print (str * 2)             # Prints string two times
print (str + "TEST")  # Prints concatenated string

This will produce the following result-
Hello World!
H
llo
llo World!
Hello World!Hello World!
Hello World!TEST

3.Python Lists
Lists are the most versatile of Python's compound data types. A list contains items separated by commas and enclosed within square brackets ([]).

#!/usr/bin/python3
list = [ 'abcd', 786 , 2.23, 'john', 70.2 ]
tinylist = [123, 'john']
print (list)                        # Prints complete list
print (list[0])                   # Prints first element of the list
print (list[1:3])                # Prints elements starting from 2nd till 3rd
print (list[2:])                  # Prints elements starting from 3rd element
print (tinylist * 2)           # Prints list two times
print (list + tinylist)       # Prints concatenated lists

This produces the following result-
['abcd', 786, 2.23, 'john', 70.200000000000003]
abcd
[786, 2.23]
[2.23, 'john', 70.200000000000003]
[123, 'john', 123, 'john']
['abcd', 786, 2.23, 'john', 70.200000000000003, 123, 'john']

4.Python Tuples
A tuple is another sequence data type that is similar to the list. A tuple consists of a number of values separated by commas. Unlike lists, however, tuples are enclosed within parenthesis.

#!/usr/bin/python3
tuple = ( 'abcd', 786 , 2.23, 'john', 70.2 )
tinytuple = (123, 'john')
print (tuple)                     # Prints complete tuple
print (tuple[0])                 # Prints first element of the tuple
print (tuple[1:3])               # Prints elements starting from 2nd till 3rd
print (tuple[2:])                 # Prints elements starting from 3rd element
print (tinytuple * 2)           # Prints tuple two times
print (tuple + tinytuple)    # Prints concatenated tuple

This produces the following result-
('abcd', 786, 2.23, 'john', 70.200000000000003)
abcd
(786, 2.23)
(2.23, 'john', 70.200000000000003)
(123, 'john', 123, 'john')
('abcd', 786, 2.23, 'john', 70.200000000000003, 123, 'john')

5.Python Dictionary
Python's dictionaries are kind of hash-table type. They work like associative arrays or hashes found in Perl and consist of key-value pairs. A dictionary key can be almost any Python type, but are usually numbers or strings. Values, on the other hand, can be any arbitrary Python object.

#!/usr/bin/python3
dict = {}
dict['one'] = "This is one"
dict[2]= "This is two"
tinydict = {'name': 'john','code':6734, 'dept': 'sales'}
print (dict['one'])                      # Prints value for 'one' key
print (dict[2])                           # Prints value for 2 key
print (tinydict)                         # Prints complete dictionary
print (tinydict.keys())              # Prints all the keys
print (tinydict.values())           # Prints all the values

This produces the following result-
This is one
This is two
{'dept': 'sales', 'code': 6734, 'name': 'john'}
['dept', 'code', 'name']
['sales', 6734, 'john']