Python has 4 different types of data collections.
- List
- Tuple
- Dictionary
- Set
The following section describes all 4 collections data type and various operation on it with examples.
List
The list is a most versatile datatype available in Python which can be written as a list of comma-separated values between square brackets. Python List allows duplicate values. An index number is used to access a particular list element.
Create a list
li = ['a','b','c','d']
Python also supports negative indexing means -1 refer to the last elements of the list, -2 refers to the second last elements of the list. You can also access the range of list elements by defining the first and last index of the range.
Tuple
A Tuple is the collection of immutable Python objects. Tuples are sequences, just like lists. But, the main difference between list and tuple is, Tuple is immutable means it isn’t allowed to change value. A tuple is written in round brackets. An index number is used to access a particular Tuple element like List.
Create a tuple
li = ('a','b','c','d')
Dictionary
A dictionary is key-value pair datatype written in curly brackets. Dictionary is unordered and changeable. Keys must be unique in the dictionary but the value may not be. You can access the dictionary value by its key.
dict = {'fruit':'apple','color':'yellow','shape':'circle','quantity':50}
Set
A set is Python’s collection which is unindexed and unordered. A set is written as a sequence of comma-separated values between {} curly brackets. Like tuple, the set is also immutable means you are not allowed to change the set elements. A set doesn’t contain any duplicate items.
Set can also be used to calculate the mathematical set operations such as union, intersection, difference, symmetric difference, etc.
set1 = {"green", "red", "blue" ,"blue"}
print(set1)
# Output
{'red', 'blue', 'green'} # It discard the duplicate elements.
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