Lists:
Lists are ordered collections that can contain elements of different types. They are mutable, meaning you can change their elements.
Example:
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my_list = [1, 2, "apple", True]
my_list.append(5) # Adding an element
print(my_list[2]) # Accessing an element by index
my_list.remove("apple") # Removing an element
print(my_list) # Printing the modified list
Dictionary:
Dictionaries are unordered collections of key-value pairs. They use keys to access their associated values and are mutable.
Example:
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my_dict = {"name": "Alice", "age": 25, "city": "New York"}
print(my_dict["age"]) # Accessing value by key
my_dict["occupation"] = "Engineer" # Adding a new key-value pair
del my_dict["city"] # Deleting a key-value pair
print(my_dict) # Printing the modified dictionary
Ranges:
Ranges are sequences of numbers used for iterating over a sequence of numbers. They are immutable and commonly used in loops.
Example:
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my_range = range(5) # Creates a range from 0 to 4
for num in my_range:
print(num) # Prints numbers from the range
Functions:
Functions in Python are blocks of code that perform a specific task. They can take parameters and return values.
Example:
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def add_numbers(a, b):
return a + b # Returns the sum of two numbers
result = add_numbers(3, 5) # Calling the function
print(result) # Printing the result
Python Built-in Functions:
Python has many built-in functions that are readily available for use without importing any modules. Examples include print(), len(), min(), max(), sum(), sorted(), enumerate(), etc.
Example:
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my_list = [3, 1, 7, 2, 5]
print(len(my_list)) # Prints the length of the list
print(sorted(my_list)) # Prints the sorted list
print(sum(my_list)) # Prints the sum of elements in the list
These concepts are fundamental in Python and form the backbone for many functionalities and data manipulation techniques.
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Lists:
Lists in Python are ordered collections of items, denoted by square brackets []. They can contain elements of different data types and are mutable.
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# Creating a list
my_list = [1, 2, 3, 'apple', 'banana', True]
# Accessing elements in a list
print(my_list[0]) # Output: 1
print(my_list[3]) # Output: 'apple'
# Modifying elements in a list
my_list[1] = 'orange' # Changing the element at index 1
print(my_list) # Output: [1, 'orange', 3, 'apple', 'banana', True]
Dictionary:
Dictionaries in Python are unordered collections of key-value pairs, enclosed in curly braces {}.
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# Creating a dictionary
my_dict = {'name': 'Alice', 'age': 25, 'city': 'New York'}
# Accessing values in a dictionary
print(my_dict['name']) # Output: 'Alice'
print(my_dict.get('age')) # Output: 25
# Modifying values in a dictionary
my_dict['city'] = 'San Francisco' # Changing the value associated with the key 'city'
print(my_dict) # Output: {'name': 'Alice', 'age': 25, 'city': 'San Francisco'}
Ranges:
range() in Python generates an immutable sequence of numbers within a specified range.
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# Creating a range
my_range = range(5) # Generates numbers from 0 to 4
# Accessing elements in a range
print(list(my_range)) # Output: [0, 1, 2, 3, 4]
Functions:
Functions in Python are blocks of reusable code that perform a specific task. They are defined using the def keyword.
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# Function definition
def greet(name):
return f"Hello, {name}!"
# Function call
print(greet('Alice')) # Output: 'Hello, Alice!'
Python Built-in Functions:
Python provides numerous built-in functions to perform various operations. Some examples include:
len(): Returns the length of an object (e.g., list, string, dictionary).
max(): Returns the maximum value in an iterable.
min(): Returns the minimum value in an iterable.
sum(): Returns the sum of all elements in an iterable.
sorted(): Returns a new sorted list from the elements of an iterable.
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my_list = [3, 1, 7, 5, 2]
print(len(my_list)) # Output: 5
print(max(my_list)) # Output: 7
print(min(my_list)) # Output: 1
print(sum(my_list)) # Output: 18
print(sorted(my_list)) # Output: [1, 2, 3, 5, 7]
These fundamental elements and built-in functions are core components in Python programming, allowing you to manipulate data, create reusable code with functions, and utilize a wide range of built-in functionalities to streamline your programs.
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