python的format函数如何使用

Python的format函数可以用来格式化字符串。以下是使用format函数的示例：

name = "Alice"age = 30message = "My name is {} and I am {} years old.".format(name, age)print(message)

输出结果为：My name is Alice and I am 30 years old.

name = "Bob"age = 25message = "My name is {name} and I am {age} years old.".format(name=name, age=age)print(message)

输出结果为：My name is Bob and I am 25 years old.

name = "Charlie"age = 20message = "My name is {0} and I am {1} years old.".format(name, age)print(message)

输出结果为：My name is Charlie and I am 20 years old.

pi = 3.14159formatted_pi = "Pi is approximately {:.2f}".format(pi)print(formatted_pi)

输出结果为：Pi is approximately 3.14

以上是使用format函数的一些常见示例，你可以根据自己的需求来选择合适的方式来格式化字符串。