2 Python Data Containers (Lists, Tuples, Dict, strings).ipynb

Kernel: Python 3 (ipykernel)

Python Data Containers

Lists

Lists are ordered collections of items, defined using square brackets [].

You can access, modify, and perform operations on lists.

a=["ashi",25,14.5]
a[0]
a[-1]
len(a)
a.append("ab")

a
del a[-1]

a

['ashi', 25, 14.5]

# Example: List operations
fruits = ["apple", "banana", "cherry"]

# Modify elements
fruits[1] = "blueberry"
print("Updated fruits:", fruits)

# Add elements
fruits.append("orange")
print("After adding:", fruits)

# Remove elements
fruits.remove("apple")
print("After removing apple:", fruits)

Updated fruits: ['apple', 'blueberry', 'cherry']
After adding: ['apple', 'blueberry', 'cherry', 'orange']
After removing apple: ['blueberry', 'cherry', 'orange']

fruits.insert(2,"Kiwi")

fruits

['blueberry', 'cherry', 'Kiwi', 'orange']

fruits+fruits
3*fruits

['blueberry',
 'cherry',
 'Kiwi',
 'orange',
 'blueberry',
 'cherry',
 'Kiwi',
 'orange',
 'blueberry',
 'cherry',
 'Kiwi',
 'orange']

a=[100,120,780]
print("sum is actually concadination:", a+a)
print("multiplication is actually repetation:",3*a)

sum is actually concadination: [100, 120, 780, 100, 120, 780]
multiplication is actually repetation: [100, 120, 780, 100, 120, 780, 100, 120, 780]

Tuples

Tuples are ordered, immutable collections of items, defined using parentheses (). Once created, the elements of a tuple cannot be changed.

# Example: Tuples
m = (1, 2, 3, 4, 5)
print("Tuple:", m)

# Access elements
print("First element:", m[0])
print("Last element:", m[-1])

Tuple: (1, 2, 3, 4, 5)
First element: 1
Last element: 5

m.append(9)
##please note: tupels are immutable

---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
Cell In[24], line 1
----> 1 m.append(9)
AttributeError: 'tuple' object has no attribute 'append'

Dictionaries

Dictionaries store data in key-value pairs, defined using curly braces {}. They are unordered, mutable, and indexed by keys.

# Example: Dictionaries
person = {"name": "alley", "age": 25, "city": "New York"}
print("Dictionary:", person)

# Access values by key
print("Name:", person["name"])

# Add new key-value pair
person["email"] = "[email protected]"
print("Updated dictionary:", person)

# Modify a value
person["age"] = 26
print("After updating age:", person)

Dictionary: {'name': 'alley', 'age': 25, 'city': 'New York'}
Name: alley
Updated dictionary: {'name': 'alley', 'age': 25, 'city': 'New York', 'email': '[email protected]'}
After updating age: {'name': 'alley', 'age': 26, 'city': 'New York', 'email': '[email protected]'}

person["Gender"]="Female"
person
person.keys()
person.values()
del person['name']

person

{'age': 26,
 'city': 'New York',
 'email': '[email protected]',
 'Gender': 'Female'}

Sets

Sets are unordered collections of unique elements, defined using curly braces {}. They are useful for mathematical operations like union, intersection, and difference.

# Example: Sets
set1 = {1, 2, 3,3, 4,4}
set2 = {13, 4, 5, 6}

print("Set1:", set1)
print("Set2:", set2)

Set1: {1, 2, 3, 4}
Set2: {13, 4, 5, 6}

set1[0] # indexing not supported in Sets

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[41], line 1
----> 1 set1[0]
TypeError: 'set' object is not subscriptable

# Union
print("Union:", set1 | set2)

# Intersection
print("Intersection:", set1 & set2)

# Difference
print("Difference (set1 - set2):", set1 - set2)

# Symmetric Difference
print("Symmetric Difference:", set1 ^ set2) ## all uncommon elements

Union: {1, 2, 3, 4, 5, 6, 13}
Intersection: {4}
Difference (set1 - set2): {1, 2, 3}
Symmetric Difference: {1, 2, 3, 5, 6, 13}

Strings

Strings are sequences of characters enclosed in single or double quotes. They support slicing, concatenation, and many built-in methods.

# Example: Strings
text = "Python Programming"
s="1234"
b="1234abc has "

# Access characters
print("First character:", text[0])
print("Last character:", text[-1])

# Slicing
print("First 6 characters:", text[:6])
print("Last 6 characters:", text[-6:])

# String methods
print("Uppercase:", text.upper())
print("Lowercase:", text.lower())
print("Replace:", text.replace("Python", "Java"))

First character: P
Last character: g
First 6 characters: Python
Last 6 characters: amming
Uppercase: PYTHON PROGRAMMING
Lowercase: python programming
Replace: Java Programming

#please note: strings are immutable
#s.append("456")
#del s[2]
del s

---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
Cell In[39], line 4
      1 #please note: strings are immutable
      2 #s.append("456")
      3 #del s[2]
----> 4 del s
      5 s
NameError: name 's' is not defined

Hands-on Quick Practice

Try solving the following problems:

1. Create a tuple of 5 numbers and print the second and fourth element.

2. Make a dictionary for storing student info (name, age, grade) and print values.

3. Use sets to find common elements between two lists.

4. Write a program to check if a word exists in a given string.

5. Convert a string to uppercase and count how many vowels it has.

# Write your practice code here