场景一:初始化一个空字符串变量 # 初始化一个空字符串变量empty_string=''print(empty_string)# 输出: '' 1. 2. 3. 场景二:将已有字符串清空 # 将已有字符串清空string='Hello, World!'string=''# 清空字符串print(string)# 输出: '' 1. 2. 3. 4. 场景三:将其他类型的变量转换为字符串 我们可...
Astringis a Python data type that’s used to represent a piece of text. It’s written between quotes, either double quotes or single quotes and can be as short as zero characters, or empty string, or as long as you wish. Strings can beconcatenatedto build longer strings using the plus...
"" # Using the str() function string_function = str(123.45) # str() converts float data type to string data type # Another str() function another_string_function = str(True) # str() converts a boolean data type to string data type # An empty string empty_string = '' # Also an...
To let a function return a value, use the return statement:Example def my_function(x): return 5 * xprint(my_function(3))print(my_function(5)) print(my_function(9)) Try it Yourself » The pass Statementfunction definitions cannot be empty, but if you for some reason have a ...
Python 有一个内置的 string 类叫做 “str”,该类包含很多方便的特性(还有一个更老的模块叫 “string”,不过我们不会用到它)。String 常量可以被双引号或者单引号包起来,不过通常会使用单引号。反斜线转义符后面带单引号和双引号表示他们的常量——如 \n \’ \”。一个被双引号包住的 String 常量里面可以出...
help(format) Help on built-in function format in module builtins: format(value, format_spec='', /) Return value.__format__(format_spec) format_spec defaults to the empty string. See the Format Specification Mini-Language section of help('FORMATTING') for details. ...
微信公众号: Python数据科学 来源:[链接]翻译总结自官方文档:[链接] Python 解释器内置了许多函数和类型,列表如下(按字母排序)(省略了几个我没用过或...
ElementTree's "findtext" function returns an empty string value if the element's text field contains an integer with value 0. Below example illustrates the issue: import xml.etree.ElementTree as ET # Create root element test = ET.Element("test") # Compute sum and difference on two numbers ...
第二个和第三个标注指出了一个重要的观点:例如'{0.mass:5.3e}'这样的格式字符串实际上使用了两种不同的表示法。冒号左边的'0.mass'是替换字段语法的field_name部分,它可以是 f-string 中的任意表达式。冒号后面的'5.3e'是格式说明符。格式说明符中使用的表示法称为格式规范迷你语言。
>>> for item in empty_list:... if not item:... print(f'Do something with the{type(item)}')...Do something with the <class 'tuple'> Do something with the <class 'str'> Do something with the <class 'list'> Do something with the <class 'dict'> Do something with the <...