Thenotoperator is a logical operator that returnsTrueif the value or expression isFalse, andFalseif the value or expression isTrue. So if we specify not before the string in the if condition, It will become True when the string is empty and False when the string is not empty. # Consider...
In both cases, if theifstatement does not find aTruevalue, then theelseblock will be executed. This file exists, ok!This is an empty file. Check Empty Excel File in Python There is a problem with the above code; we have an empty file, but its size is not 8kb. It is seen withCS...
This is basically a manually implemented truth value test. So if the list is not empty the function will return True and if block will be executed. This approach is less common as we can achieve the desired results even without using bool(), but it's not a bad thing to know how Pyth...
Check if a String is Empty or Whitespace in Python Using the Equality Operator To check if a string is empty using the equality operator, we can just compare the string with another empty string. If the result is True, the input string is empty. Otherwise not. input_string="" print("Th...
第3 节:用于 Web 开发的不同深度学习 API 入门 本节将说明 API 在软件开发中的一般用法,并说明如何使用不同的最新深度学习 API 来构建智能 Web 应用。 我们将涵盖自然语言处理(NLP)和计算机视觉等领域。 本节包括以下章节: “第 5 章”,“通过 API 进行深度学习” “第 6 章”,“使用 Python 在 Google...
类图如下所示: 1*111111ifFunction- condition+ifNotEmpty()x- valueNonelenFunction+checkLength()lenResult- length 希望本文能够帮助你理解如何使用Python中的if语句来判断变量是否为空。如果你有任何问题,欢迎在评论区留言。感谢阅读! 参考文献:
字典是一系列由键(key)和值(value)配对组成的元素的集合,在Python3.7+,字典被确定为有序(注意:在3.6中,字典有序是一个implementation detail,在3.7才正式成为语言特性,因此3.6中无法100%确保其有序性),而3.6之前是无序的,其长度大小可变,元素可以任意地删减和改变。 相比于列表和元组,字典的性能更优,特别是...
('Import configuration file.') if export_value is not None: self.exportcfg = export_value def print_startup_info(self): def get_info_str(info): return str(info) print_info = "Startup information of the current device:\n" print_info += "{: <26}{: <68}{: <68}\n".format('...
5print'x is',x 6x=2 7print'Changed local x to',x 8x=50 9func() 10print'Value of x is',x 11(源文件:code/func_global.py) 12输出 13$ python func_global.py 14xis50 15Changedglobalx to2 16Value of xis2 默认参数值 你可以在函数定义的形参名后 加上赋值运算符(=)和默认值,从而给...
fromenumimportEnumclassStatus(Enum):NO_STATUS=-1NOT_STARTED=0IN_PROGRESS=1COMPLETED=2print(Status.IN_PROGRESS.name)# IN_PROGRESSprint(Status.COMPLETED.value)# 2 ▍9、重复字符串 name="Banana"print(name*4)# BananaBananaBananaBanana ▍10、比较3个数字的大小 ...