Specific use of Python built-in function map

In Pythonmap()A function is a built-in function that maps the specified sequence based on the provided functions.

Function definition

map()The basic syntax of a function is as follows:

map(function, iterable, ...)

function: A function,map()Will beiterableEach item in it is passed to this function.
iterable: One or more sequences,map()It will be iterated.

map()The function returns an iterator, which is generated byfunctionApplied toiterableThe result of each item.

Basic usage

Single sequence

def square(number):
    return number ** 2

numbers = [1, 2, 3, 4, 5]
squared = map(square, numbers)

print(list(squared))  # Output: [1, 4, 9, 16, 25]

Multiple sequences

def add(a, b):
    return a + b

nums1 = [1, 2, 3]
nums2 = [4, 5, 6]
result = map(add, nums1, nums2)

print(list(result))  # Output: [5, 7, 9]

Advanced Usage

Combined with lambda functions

map()Often with anonymous functionslambdaUse together to create clean code.

numbers = [1, 2, 3, 4, 5]
squared = map(lambda x: x ** 2, numbers)

print(list(squared))  # Output: [1, 4, 9, 16, 25]

Using multiple iterators

You can pass multiple iterators tomap(), functions will take values from these iterators in parallel.

a = [1, 2, 3]
b = [4, 5, 6]
c = [7, 8, 9]

result = map(lambda x, y, z: x + y + z, a, b, c)

print(list(result))  # Output: [12, 15, 18]

Things to note

iffunctionGivenNone，map()Will return directlyiterableelements in.
ifiterableThe lengths are different,map()Will stop at the end of the shortest sequence.

in conclusion

map()It is a very useful built-in function in Python, which provides a convenient way to convert and manipulate elements in a sequence. Through the above routine, we can seemap()Applications in real programming and how to use it effectively to simplify code and improve efficiency.

This is all about this article about the built-in Python function map(). For more related Python map() content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!