python中format

# 示例代码：使用 format 方法格式化字符串

# 简单的字符串格式化
name = "Alice"
age = 30
formatted_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.

# 使用索引指定参数位置
formatted_string_with_index = "My name is {1} and I am {0} years old.".format(age, name)
print(formatted_string_with_index)  # 输出: My name is Alice and I am 30 years old.

# 使用命名参数
person = {'name': 'Bob', 'age': 25}
formatted_string_with_named_args = "My name is {name} and I am {age} years old.".format(**person)
print(formatted_string_with_named_args)  # 输出: My name is Bob and I am 25 years old.

# 格式化数字
pi = 3.141592653589793
formatted_pi = "The value of pi is approximately {:.2f}".format(pi)
print(formatted_pi)  # 输出: The value of pi is approximately 3.14

# 对齐和填充
text = "hello"
formatted_text = "{:^10}".format(text)  # 居中对齐，总长度为10
print(formatted_text)  # 输出:   hello   

# 填充字符
formatted_text_with_fill = "{:*^10}".format(text)  # 使用 * 填充并居中对齐
print(formatted_text_with_fill)  # 输出: **hello***

以上代码展示了 Python 中 format 方法的多种用法，包括简单的字符串格式化、使用索引和命名参数、格式化数字以及对齐和填充等。