Tuple

A tuple is similar to a list. The difference between the two is that we cannot change the elements of a tuple once it is created whereas in a list, elements can be changed.

Create tuple

>>> tu=(1,2,3,4,5)
>>> tu
(1, 2, 3, 4, 5)

Tuple vs List

Tuple List
immutable -Once created contents cannot be changed mutable -contents can be changed
Generally use tuple for heterogeneous (different) datatypes list for homogeneous (similar) datatypes.
Example: date_of_birth=(10,"aug",2000) Example: heights=[150,160,170]
Iteration is slightly faster than list relatively slower than tuple 
>>> li=[1,2,3,4]
>>> li.append(5)
>>> li                                                     
[1, 2, 3, 4, 5]
>>> tu=(1,2,3,4)                                           
>>> tu.append(5) # Once created they cannot be changed                                          
Traceback (most recent call last):                         
  File "<stdin>", line 1, in <module>                      
AttributeError: 'tuple' object has no attribute 'append'   
>>>

Accessing elements

Elements can be accessed with index

>>> tu=(10,"aug",2000)
>>> tu[0]              
10

Negative Index is also supported

>>> tu[-1]
2000

Slicing or sub tuple

We can access a range of items in a tuple by using the slicing operator - colon ":". General syntax

tu[start : end : step]
>>> tu=(1,2,3,4) # Create a tuple
>>> tu[:] # Get all elements in the tuple, Note start and end are optional
(1, 2, 3, 4)
>>> tu[:-1] # Get all the elements from start  
(1, 2, 3)
>>> tu[0:] #Get all the elements till end
(1, 2, 3, 4)
>>> tu[0:1] # Get first element in the tuple
(1,)
>>> tu[0:-1:2] # You can specify step size as well 
(1, 3)

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