1. 字符串
str1 = "Hello"str2 = " World"print(str1 + str2) # 输出：HelloWorld
1.1 字符替换
text = "Hello, World!"new_text = text.replace("World", "Python")print(new_text) # 输出：Hello, Python!
1.2 字符串方法 - 大小写转换
text = "hello world"upper_text = text.upper()lower_text = text.lower()print(upper_text) # 输出：HELLO WORLDprint(lower_text) # 输出：hello world
1.3 字符串格式化 - 使用format方法
name = "Alice"age = 30formatted_string = "My name is {} and I am {} years old.".format(name, age)print(formatted_string) # 输出：My name is Alice and I am 30 years old.
1.4 字符串格式化 - f-string
name = "Alice"age = 30formatted_string = f"My name is {name} and I am {age} years old."print(formatted_string) # 输出：My name is Alice and I am 30 years old.
2. 列表
my_list = [1, 2, 3, 4, 5]print(my_list)
2.1 访问列表
my_list = [1, 2, 3, 4, 5]print(my_list[0]) # 输出第一个元素
2.2 修改列表
my_list = [1, 2, 3, 4, 5]my_list[0] = 10print(my_list)
2.3 追加元素
my_list = [1, 2, 3, 4, 5]my_list.append(6)print(my_list)
2.3 列表排序
numbers = [5, 1, 9, 3, 7]numbers.sort()print(numbers) # 输出：[1, 3, 5, 7, 9]
2.4 列表反转
numbers = [1, 2, 3, 4, 5]numbers.reverse()print(numbers) # 输出：[5, 4, 3, 2, 1]
3. 元组
my_tuple = (1, 2, 3, 4, 5)print(my_tuple)
3.1 访问元组
my_tuple = (1, 2, 3, 4, 5)# 访问第一个元素first_element = my_tuple[0]print(first_element) # 输出：1# 访问最后一个元素last_element = my_tuple[-1]print(last_element) # 输出：5
3.2 元组切片
my_tuple = (1, 2, 3, 4, 5, 6, 7, 8, 9)# 切片获取部分元素sub_tuple = my_tuple[2:5]print(sub_tuple) # 输出：(3, 4, 5)
3.3 元组不可变性
my_tuple = (1, 2, 3)# 尝试修改元组元素，这会抛出异常# my_tuple[0] = 10 # 这行会引发TypeError# 正确的方式是创建新的元组new_tuple = (10,) + my_tuple[1:]print(new_tuple) # 输出：(10, 2, 3)
3.4 元组与列表的转换
# 将列表转换为元组my_list = [1, 2, 3]my_tuple = tuple(my_list)print(my_tuple) # 输出：(1, 2, 3)# 将元组转换为列表my_tuple = (1, 2, 3)my_list = list(my_tuple)print(my_list) # 输出：[1, 2, 3]
3.5 元组作为字典的键
# 元组可以作为字典的键，因为元组是不可变的my_dict = {(1, 2): "one-two", (3, 4): "three-four"}print(my_dict[(1, 2)]) # 输出："one-two"
3.6 元组解包
# 解包元组到变量中a, b, c = (1, 2, 3)print(a) # 输出：1print(b) # 输出：2print(c) # 输出：3# 解包带有星号的元组first, *rest = (1, 2, 3, 4, 5)print(first) # 输出：1print(rest) # 输出：[2, 3, 4, 5]
4. 字典
my_dict = {"name": "Alice", "age": 30}print(my_dict["name"])
4.1 字典更新
my_dict = {"name": "Alice", "age": 30}my_dict["age"] = 31print(my_dict)
4.2 字典的get方法
my_dict = {'a': 1,'b': 2}value = my_dict.get('a')print(value) # 输出：1value = my_dict.get('c', 'Not found')print(value) # 输出：Not found
4.3 字典的keys()和values()方法
my_dict = {'a': 1, 'b': 2, 'c': 3}keys = my_dict.keys()values = my_dict.values()print(keys) # 输出：dict_keys(['a', 'b', 'c'])print(values) # 输出：dict_values([1, 2, 3])
5. 集合
my_set = {1, 2, 3, 4, 5}print(my_set)
5.1 集合操作 - 并集
set1 = {1, 2, 3}set2 = {3, 4, 5}union_set = set1 | set2print(union_set)
5.2 集合操作 - 交集
set1 = {1, 2, 3}set2 = {3, 4, 5}intersection_set = set1 & set2print(intersection_set)
6. 推导式
6.1 列表推导式
squares = [x**2 for x in range(5)]print(squares) # 输出：[0, 1, 4, 9, 16]
6.2 字典推导式
my_dict = {'a': 1, 'b': 2, 'c': 3}new_dict = {k: v*2 for k, v in my_dict.items()}print(new_dict) # 输出：{'a': 2, 'b': 4, 'c': 6}
6.3 条件推导式
numbers = [1, 2, 3, 4, 5]evens = [num for num in numbers if num % 2 == 0]print(evens) # 输出：[2, 4]
7. 四大函数
7.1 enumerate函数
my_list = ['a', 'b', 'c']for index, value in enumerate(my_list):print(f"Index: {index}, Value: {value}")
7.2 zip函数
list1 = [1, 2, 3]list2 = ['a', 'b', 'c']for i, j in zip(list1, list2):print(i, j)
7.3 map函数
numbers = [1, 2, 3, 4, 5]squared = map(lambda x: x**2, numbers)print(list(squared)) # 输出：[1, 4, 9, 16, 25]
7.4 filter函数
numbers = [1, 2, 3, 4, 5, 6]even_numbers = filter(lambda x: x % 2 == 0, numbers)print(list(even_numbers)) # 输出：[2, 4, 6]
8. 条件语句
x = 10if x > 5:print("x is greater than 5")
9. 循环语句
9.1 for循环
for i in range(5):print(i)
9.2 while循环
i = 0while i < 5:print(i)i += 1
10. 异常处理
try:x = 1 / 0except ZeroDivisionError:print("Cannot divide by zero")
11. 文件读写
11.1 文件读取
with open('example.txt', 'r') as file:content = file.read()print(content)
11.2 文件写入
with open('example.txt', 'w') as file:file.write('Hello, World!')
12. 模块导入
import mathprint(math.sqrt(16)) # 输出：4.0
13. 函数
def greet(name):print(f"Hello, {name}!")greet("Bob")
14. 类
class Dog:def __init__(self, name):self.name = namedef bark(self):print(f"{self.name} barks!")my_dog = Dog("Buddy")my_dog.bark() # 输出：Buddy barks!
15. 继承
class Animal:def __init__(self, name):self.name = namedef speak(self):print(f"{self.name} speaks!")class Dog(Animal):def bark(self):print(f"{self.name} barks!")my_dog = Dog("Buddy")my_dog.speak() # 输出：Buddy speaks!my_dog.bark() # 输出：Buddy barks!
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