Introduction to Python functions: usage and examples of min function

Introduction to Python functions: Usage and examples of min function

The min function is one of the built-in functions in Python, and its function is to return the minimum value among the given parameters. The usage and examples of the min function will be introduced in detail below, and code examples will be given.

1. Basic usage of min function

The basic usage of min function is as follows:

min(iterable, *[, default=obj, key=func])

Among them, iterable is a required parameter, indicating the iterable object to be compared; * means that it can be followed by multiple keyword parameters, of which only default and key are commonly used.

1. default parameter

The default parameter indicates the default value that the min function should return when iterable is empty. If this value is not specified, a ValueError exception will be thrown directly. . For example:

nums = []
min(nums, default=0)  # 返回默认值0

2. key parameter

The key parameter represents the function to be applied to each element so that comparisons can be made based on the function return value. For example:

fruits = ["apple", "banana", "orange", "watermelon"]
min(fruits, key=len)  # 返回长度最小的水果名"apple"

2. Example of min function

1. Get the minimum value in the list

When you need to get the minimum value in a list, You can use the min function directly, as shown below:

nums = [5, 3, 1, 7, 9, 2, 4]
print(min(nums))  # 输出1

2. Get the minimum ASCII code in the string

You can split the string into each character, and Convert it to ASCII code for comparison to obtain the minimum value of the ASCII code in the string, as shown below:

string = "hello world"
print(min(string))  # 输出空格" "

3. Get the minimum value of a certain attribute in the list

When you need to get the minimum value according to a certain attribute in a custom object list, you can use the key parameter to specify the comparison according to the attribute, as shown below:

class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age

    def __str__(self):
        return self.name

people = [Person("Tom", 20),
          Person("Jerry", 18),
          Person("Adam", 22)]
print(min(people, key=lambda x: x.age))  # 输出年龄最小的Jerry

4. Get the minimum value in the dictionary The key corresponding to the value

When you need to obtain the key corresponding to the minimum value in a dictionary, you can use the key parameter to specify the comparison according to the value, as shown below:

dict_data = {"a": 3, "b": 1, "c": 5, "d": 4}
print(min(dict_data, key=dict_data.get))  # 输出值最小的键"b"

The above is about The introduction and examples of Python function min, I hope it will be helpful to everyone.

The above is the detailed content of Introduction to Python functions: usage and examples of min function. For more information, please follow other related articles on the PHP Chinese website!