62个 Python 常用函数,从基础到进阶(一)
print("Hello, World!") # 输出: Hello, World!name = input("请输入您的姓名：") print("您的姓名是：" + name)二、数据类型与转换
- 3.len()：返回对象的长度或元素个数
string = "Hello, World!" length = len(string) print(length) # 输出: 13number = 42 string = str(number) print(string) # 输出: '42'string = "42" number = int(string) print(number) # 输出: 42string = "3.14" number = float(string) print(number) # 输出: 3.14number = 42 print(type(number)) # 输出: intstring = "Hello" char_list = list(string) print(char_list) # 输出: ['H', 'e', 'l', 'l', 'o']list_data = [1, 2, 3] tuple_data = tuple(list_data) print(tuple_data) # 输出: (1, 2, 3)person = dict(name='Alice', age=25) print(person) # 输出: {'name': 'Alice', 'age': 25}numbers = [1, 2, 3, 2, 1] unique_numbers = set(numbers) print(unique_numbers) # 输出: {1, 2, 3}12.range()：生成一个指定范围内的整数序列for num in range(1, 5): print(num) # 输出: 1 2 3 4numbers = [1, 2, 3, 4, 5] total = sum(numbers) print(total) # 输出: 15numbers = [1, 2, 3, 4, 5] maximum = max(numbers) print(maximum) # 输出: 5numbers = [1, 2, 3, 4, 5] minimum = min(numbers) print(minimum) # 输出: 1number = -42 absolute = abs(number) print(absolute) # 输出: 42number = 3.14159 rounded = round(number, 2) print(rounded) # 输出: 3.14result = pow(2, 3) print(result) # 输出: 8quotient, remainder = divmod(10, 3) print(quotient, remainder) # 输出: 3 120.replace()：替代字符串中的某一些子串为另一些字st = "i want a apple" st = st.replace("apple", "nice") print(st) # 输出: i want a nicest = " hello " st = st.strip() print(st+"end") # 输出: helloend22.sorted()：返回一个排序后的可迭代对象numbers = [5, 2, 4, 1, 3] sorted_numbers = sorted(numbers) print(sorted_numbers) # 输出: [1, 2, 3, 4, 5]23.reversed()：返回一个反转后的可迭代对象numbers = [1, 2, 3, 4, 5] reversed_numbers = list(reversed(numbers)) print(reversed_numbers) # 输出: [5, 4, 3, 2, 1]24.zip()：将多个可迭代对象按索引位置组合成元组names = ['Alice', 'Bob', 'Charlie'] ages = [25, 30, 35] zipped = list(zip(names, ages)) print(zipped) # 输出: [('Alice', 25), ('Bob', 30), ('Charlie', 35)]25.enumerate()：返回可迭代对象中元素的索引和值names = ['Alice', 'Bob', 'Charlie'] for index, name in enumerate(names): print(f"Name at index {index}: {name}")26.any()：判断可迭代对象中是否存在任何为真的元素numbers = [0, 1, 2, 3] print(any(numbers)) # 输出: True27.all()：判断可迭代对象中所有元素是否都为真numbers = [0, 1, 2, 3] print(all(numbers)) # 输出: False28.slice()：返回一个切片对象，用于切片操作numbers = [0, 1, 2, 3, 4, 5] sliced = numbers[slice(2, 5)] print(sliced) # 输出: [2, 3, 4]29.filter()：使用函数过滤可迭代对象中的元素numbers = [1, 2, 3, 4, 5] even_numbers = list(filter(lambda x:x%2==0,numbers)) print(even_numbers) # 输出: [2, 4]30.map()：使用函数对可迭代对象中的每个元素进行映射numbers = [1, 2, 3, 4, 5] squared_numbers = list(map(lambda x:x**2,numbers)) print(squared_numbers) # 输出: [1, 4, 9, 16, 25]31.reduce()：使用函数对可迭代对象中的元素进行累积计算from functools import reduce numbers = [1, 2, 3, 4, 5] product = reduce(lambda x, y: x * y, numbers) print(product) # 输出: 120
