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# 1234567890- = 10`~
# +1_2)3(4*5&6 ^7%8$9#0@[!]{\}; : '>",.?./\
# Lambda functions, also known as anonymous functions, are small, unnamed functions defined using the lambda keyword.
# The syntax is: lambda arguments: expression
# Lambda functions can have any number of arguments but only one expression.
# Here's a simple lambda function that takes two arguments and returns their sum:
sum_lambda = lambda x, y: x + y
# Test the lambda function:
result = sum_lambda(5, 3)
print(f"Sum of 5 and 3 is: {result}") # Outputs: 8
# Lambda functions are often used for short operations that can be encapsulated in a single expression.
# One common use case is with the `sorted` function and its `key` argument.
# Consider a list of tuples where each tuple contains a name and age:
people = [("Alice", 30), ("Bob", 25), ("Charlie", 35), ("Dana", 28)]
# To sort this list by age, you can use a lambda function:
sorted_people = sorted(people, key=lambda person: person[1])
# Print sorted list:
print(sorted_people) # Outputs: [('Bob', 25), ('Dana', 28), ('Alice', 30), ('Charlie', 35)]
# Lambda functions are meant for simple operations. If the operation is complex, it's usually better to use a regular function.
# Let's demonstrate using a lambda with the `filter` function:
# We want to filter out people older than 28
young_people = filter(lambda person: person[1] <= 28, people)
# Convert the filter object to a list and print it:
print(list(young_people)) # Outputs: [('Alice', 30), ('Bob', 25), ('Dana', 28)]
# Lambda functions are powerful for quick operations, especially in combination with functions like `sorted`, `filter`, and `map`.
# 1234567890- = 10`~
# +1_2)3(4*5&6 ^7%8$9#0@[!]{\}; : '>",.?./\
# Defining a normal function to replace the lambda function for sum.
def sum_function(x, y):
return x + y
# Test the normal function:
result = sum_function(5, 3)
print(f"Sum of 5 and 3 is: {result}") # Outputs: 8
# Consider a list of tuples where each tuple contains a name and age:
people = [("Alice", 30), ("Bob", 25), ("Charlie", 35), ("Dana", 28)]
# Defining a normal function to replace the lambda function for sorting by age.
def age_key(person):
return person[1]
# Sorting the list by age using the normal function:
sorted_people = sorted(people, key=age_key)
# Print sorted list:
print(sorted_people) # Outputs: [('Bob', 25), ('Dana', 28), ('Alice', 30), ('Charlie', 35)]
# Defining a normal function to replace the lambda function for filtering people older than 28.
def is_young(person):
return person[1] <= 28
# Filtering out people using the normal function:
young_people = filter(is_young, people)
# Convert the filter object to a list and print it:
print(list(young_people)) # Outputs: [('Alice', 30), ('Bob', 25), ('Dana', 28)]