5.1 Lists 5.1.1
Creating and accessing lists Explanation: Lists are ordered collections of
items that can be of different data types. They can be created using square
brackets and accessed using indexing and slicing. Example:
python
///Example
fruits =
["apple", "banana", "orange"]
print(fruits[0]) # Accessing the first element
print(fruits[1:3]) # Slicing to get a sublist
5.1.2 Modifying lists:
adding, removing, and updating elements Explanation: Lists are mutable, which
means their elements can be modified. Elements can be added using append(),
removed using remove() or del, and updated using assignment. Example:
python
///Example
fruits =
["apple", "banana", "orange"]
fruits.append("grape") # Adding a new element
fruits.remove("banana") # Removing an element
fruits[0] =
"kiwi" # Updating an element
print(fruits)
5.1.3 List operations:
concatenation, repetition, and length Explanation: Lists can be concatenated
using the + operator, repeated using the * operator, and their length can be
obtained using the len() function. Example:
python
///Example
list1 = [1, 2, 3]
list2 = [4, 5, 6]
result = list1 +
list2 # Concatenation
print(result)
list3 = [0] * 4 # Repetition
print(list3)
length =
len(result) # Length
print(length)
5.2 Tuples 5.2.1
Creating and accessing tuples Explanation: Tuples are similar to lists but are
immutable, meaning their elements cannot be modified. They can be created using
parentheses and accessed using indexing and slicing. Example:
python
///Example
person =
("Alice", 25, "New York")
print(person[0]) # Accessing the first element
print(person[1:]) # Slicing to get a subtuple
5.2.2 Tuple packing and
unpacking Explanation: Tuple packing allows you to create a tuple by grouping
multiple values together. Tuple unpacking allows you to assign the elements of
a tuple to individual variables. Example:
python
///Example
person =
("Alice", 25, "New York")
name, age, city =
person # Unpacking
print(name)
print(age)
print(city)
tuple1 = 1, 2, 3 # Packing
print(tuple1)
5.3 Dictionaries 5.3.1
Creating and accessing dictionaries Explanation: Dictionaries are unordered
collections of key-value pairs. They can be created using curly braces or the
dict() constructor and accessed using keys. Example:
python
///Example
student =
{"name": "Alice", "age": 20, "grade":
"A"}
print(student["name"]) # Accessing value using key
5.3.2 Modifying
dictionaries: adding, removing, and updating key-value pairs Explanation: Dictionaries
are mutable, so their key-value pairs can be added, removed, or updated using
assignment and the del keyword. Example:
python
///Example
student =
{"name": "Alice", "age": 20, "grade":
"A"}
student["city"]
= "New York" # Adding a new
key-value pair
del
student["grade"] # Removing a
key-value pair
student["age"]
= 21 # Updating a value
print(student)
5.3.3 Dictionary
operations: keys, values, and length Explanation: Dictionaries provide methods
to access keys, values, and obtain the length of the dictionary using len().
Example:
python
///Example
student =
{"name": "Alice", "age": 20, "grade":
"A"}
keys =
student.keys() # Getting keys
values =
student.values() # Getting values
length =
len(student) # Length
print(keys)
print(values)
print(length)
This chapter covers the
fundamental data structures in Python: lists, tuples, and dictionaries. Lists
are ordered collections that can be modified, tuples are immutable collections,
and dictionaries are unordered key-value pairs. The examples provided
demonstrate the usage and syntax of each topic, helping readers understand how
to apply these concepts in their own programs.
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