Python中的format()函数是一种将变量插入字符串的方法,能够使字符串更易于阅读和理解。它支持许多不同的用法,以下是具体的用法和说明:
使用位置参数传递变量
name = 'John' age = 25 print('My name is {}, and I am {} years old.'.format(name, age)) # 输出:My name is John, and I am 25 years old.
使用索引传递变量
name = 'John' age = 25 print('My name is {0}, and I am {1} years old.'.format(name, age)) # 输出:My name is John, and I am 25 years old.
使用关键字参数传递变量
name = 'John' age = 25 print('My name is {n}, and I am {a} years old.'.format(n=name, a=age)) # 输出:My name is John, and I am 25 years old.
格式化数字
price = 19.99 print('The price is ${:.2f}'.format(price)) # 输出:The price is $19.99
对齐文本
text = 'Hello' print('{:>10}'.format(text)) # 右对齐输出,总宽度为10 # 输出: Hello print('{:^10}'.format(text)) # 居中输出,总宽度为10 # 输出: Hello print('{:<10}'.format(text)) # 左对齐输出,总宽度为10 # 输出:Hello
使用格式化字符串(Python 3.6及以上版本)
name = 'John' age = 25 print(f'My name is {name}, and I am {age} years old.') # 输出:My name is John, and I am 25 years old.
使用字典传递变量
person = {'name': 'John', 'age': 25} print('My name is {name}, and I am {age} years old.'.format(**person)) # 输出:My name is John, and I am 25 years old.
使用下标操作符获取列表中的元素
fruits = ['apple', 'banana', 'cherry'] print('My favorite fruit is {0[1]}'.format(fruits)) # 输出:My favorite fruit is banana
使用花括号转义
print('{{Hello}}'.format()) # 输出:{Hello}
使用冒号分隔格式字符串和变量名称,对变量进行进一步格式化
name = 'John' score = 95 print('Student: {0:<10} Score: {1:.2f}'.format(name, score)) # 输出:Student: John Score: 95.00
根据变量类型自动选择格式
x = 42 y = 3.14 print('x is {!r}, y is {!s}'.format(x, y)) # 输出:x is 42, y is 3.14
使用填充字符
x = 42 print('{:0>5}'.format(x)) # 右对齐,用 0 填充,总宽度为 5 # 输出:00042
根据变量类型选择不同的进制输出
x = 42 print('bin: {0:b}, oct: {0:o}, hex: {0:x}'.format(x)) # 输出:bin: 101010, oct: 52, hex: 2a
自定义格式化函数
def format_salary(salary): if salary > 10000: return '{:.1f}K'.format(salary / 1000) else: return '${:,.2f}'.format(salary) print(format_salary(5000)) # $5,000.00 print(format_salary(15000)) # 15.0K
使用 ** 和 * 进行动态参数传递
data = {'name': 'John', 'age': 25} print('{name} is {age} years old.'.format(**data)) # John is 25 years old. fruits = ['apple', 'banana', 'cherry'] print('My favorite fruits are {}, {} and {}.'.format(*fruits)) # My favorite fruits are apple, banana and cherry.
以上是Python中的字串格式化方式:format()函數的使用方法的詳細內容。更多資訊請關注PHP中文網其他相關文章!