python return用法的例子

1. 返回一个数的平方：

def square(num):
    return num*num

result = square(5)
print(result) # 输出 25

2. 返回一个列表中的最大值：

def max_number(numbers):
    max_num = numbers[0]
    for num in numbers:
        if num > max_num:
            max_num = num
    return max_num

result = max_number([3, 5, 2, 8, 1])
print(result) # 输出 8

3. 返回一个字符串中每个单词的首字母大写：

def capitalize_words(sentence):
    words = sentence.split()
    capitalized_words = []
    for word in words:
        capitalized_words.append(word.capitalize())
    return " ".join(capitalized_words)

result = capitalize_words("this is a sentence")
print(result) # 输出 "This Is A Sentence"

4. 返回一个字典中特定键对应的值：

def get_value(dict, key):
    if key in dict:
        return dict[key]
    else:
        return None

result = get_value({"name": "John", "age": 30}, "age")
print(result) # 输出 30