Day 20 - Introduction to Tuples
Table of contents
- Python Tuples
- Tuple Indexes
- Example:
- Accessing tuple items:
- III. Check for item:
- Example 1:
- Output:
- Example 2:
- Output:
- IV. Range of Index:
- Syntax:
- Example: Printing elements within a particular range:
- Output:
- Example: Printing all element from a given index till the end
- Output:
- Example: printing all elements from start to a given index
- Output:
- Example: Print alternate values
- Output:
- Example: Printing every 3rd consecutive withing given range
- Output:
Python Tuples
Tuples are ordered collection of data items. They store multiple items in a single variable. Tuple items are separated by commas and enclosed within round brackets (). Tuples are unchangeable meaning we can not alter them after creation.
Example 1:
tuple1 = (1,2,2,3,5,4,6)
tuple2 = ("Red", "Green", "Blue")
print(tuple1)
print(tuple2)
Output:
(1, 2, 2, 3, 5, 4, 6)
('Red', 'Green', 'Blue')
Example 2:
details = ("Abhijeet", 18, "FYBScIT", 9.8)
print(details)
Output:
('Abhijeet', 18, 'FYBScIT', 9.8)
Tuple Indexes
Each item/element in a tuple has its own unique index. This index can be used to access any particular item from the tuple. The first item has index [0], second item has index [1], third item has index [2] and so on.
Example:
country = ("Spain", "Italy", "India",)
# [0] [1] [2]
Accessing tuple items:
I. Positive Indexing:
As we have seen that tuple items have index, as such we can access items using these indexes.
Example:
country = ("Spain", "Italy", "India",)
# [0] [1] [2]
print(country[0])
print(country[1])
print(country[2])
Output:
Spain
Italy
India
II. Negative Indexing:
Similar to positive indexing, negative indexing is also used to access items, but from the end of the tuple. The last item has index [-1], second last item has index [-2], third last item has index [-3] and so on.
Example:
country = ("Spain", "Italy", "India", "England", "Germany")
# [0] [1] [2] [3] [4]
print(country[-1]) # Similar to print(country[len(country) - 1])
print(country[-3])
print(country[-4])
Output:
Germany
India
Italy
III. Check for item:
We can check if a given item is present in the tuple. This is done using the in
keyword.
Example 1:
country = ("Spain", "Italy", "India", "England", "Germany")
if "Germany" in country:
print("Germany is present.")
else:
print("Germany is absent.")
Output:
Germany is present.
Example 2:
country = ("Spain", "Italy", "India", "England", "Germany")
if "Russia" in country:
print("Russia is present.")
else:
print("Russia is absent.")
Output:
Russia is absent.
IV. Range of Index:
You can print a range of tuple items by specifying where do you want to start, where do you want to end and if you want to skip elements in between the range.
Syntax:
Tuple[start : end : jumpIndex]
Note: jump Index is optional. We will see this in given examples.
Example: Printing elements within a particular range:
animals = ("cat", "dog", "bat", "mouse", "pig", "horse", "donkey", "goat", "cow")
print(animals[3:7]) #using positive indexes
print(animals[-7:-2]) #using negative indexes
Output:
('mouse', 'pig', 'horse', 'donkey')
('bat', 'mouse', 'pig', 'horse', 'donkey')
Here, we provide index of the element from where we want to start and the index of the element till which we want to print the values. Note: The element of the end index provided will not be included.
Example: Printing all element from a given index till the end
animals = ("cat", "dog", "bat", "mouse", "pig", "horse", "donkey", "goat", "cow")
print(animals[4:]) #using positive indexes
print(animals[-4:]) #using negative indexes
Output:
('pig', 'horse', 'donkey', 'goat', 'cow')
('horse', 'donkey', 'goat', 'cow')
When no end index is provided, the interpreter prints all the values till the end.
Example: printing all elements from start to a given index
animals = ("cat", "dog", "bat", "mouse", "pig", "horse", "donkey", "goat", "cow")
print(animals[:6]) #using positive indexes
print(animals[:-3]) #using negative indexes
Output:
('cat', 'dog', 'bat', 'mouse', 'pig', 'horse')
('cat', 'dog', 'bat', 'mouse', 'pig', 'horse')
When no start index is provided, the interpreter prints all the values from start up to the end index provided.
Example: Print alternate values
animals = ("cat", "dog", "bat", "mouse", "pig", "horse", "donkey", "goat", "cow")
print(animals[::2]) #using positive indexes
print(animals[-8:-1:2]) #using negative indexes
Output:
('cat', 'bat', 'pig', 'donkey', 'cow')
('dog', 'mouse', 'horse', 'goat')
Here, we have not provided start and end index, which means all the values will be considered. But as we have provided a jump index of 2 only alternate values will be printed.
Example: Printing every 3rd consecutive withing given range
animals = ("cat", "dog", "bat", "mouse", "pig", "horse", "donkey", "goat", "cow")
print(animals[1:8:3])
Output:
('dog', 'pig', 'goat')
Here, jump index is 3. Hence it prints every 3rd element within given index.