更改字符串

text = "Hello, world!"
new_text = text.replace("world", "Python")
print(new_text)  # 输出：Hello, Python!

name = "Alice"
age = 30

# 使用 str.format() 方法
greeting1 = "Hello, my name is {name} and I am {age} years old.".format(name=name, age=age)
print(greeting1)  # 输出：Hello, my name is Alice and I am 30 years old.

# 使用 f-string
greeting2 = f"Hello, my name is {name} and I am {age} years old."
print(greeting2)  # 输出：Hello, my name is Alice and I am 30 years old.

first_name = "John"
last_name = "Doe"

# 使用 + 运算符
full_name1 = first_name + " " + last_name
print(full_name1)  # 输出：John Doe

# 使用 str.join() 方法
full_name2 = " ".join([first_name, last_name])
print(full_name2)  # 输出：John Doe

text = "Hello, world!"
substring = text[0:5]
print(substring)  # 输出：Hello

text = "apple,banana,orange"
fruits = text.split(",")
print(fruits)  # 输出：['apple', 'banana', 'orange']