表示Variable可以是null或非null的情况。 状态图 下面是一个使用Mermaid语法的状态图,展示了Python变量是否为null if的状态流转: variable is Nonevariable is not NoneNullNullOperationNotNullNotNullOperation 在上述状态图中,起始状态为[*],表示待检查的变量。如果变量为null,则状态流转到Null状态,执行null时的操作;如果变量为非null,则状态流转到NotNull状...
ifvariableisNone:print("变量为空") 1. 2. 在上面的代码示例中,我们使用is关键字来判断变量variable是否为空。如果条件成立,即变量等于None,则打印出"变量为空"。 完整示例代码 下面是完整的示例代码,展示了如何实现“python if 条件等于null”: # 定义变量variable=None# 条件判断ifvariableisNone:print("变量...
Note python has this really weird error if you define local variable in a function same name as the global variable, program will promptUnboundLocalError. child class object overrides parent class methods input: classfruit:defprint(self):print('a')defeat(self):print('b')classapple(fruit):defpr...
AI代码解释 num=[1,4,-5,10,-7,2,3,-1]defsquare_generator(optional_parameter):return(x**2forxinnumifx>optional_parameter)printsquare_generator(0)#<generator object<genexpr>at0x004E6418># OptionIforkinsquare_generator(0):print k #1,16,100,4,9# OptionIIg=list(square_generator(0))print ...
if 写一个条件语句 import 导入模块 in 检查列表、元组等集合中是否存在某个值 is 测试两个变量是否相等 lambda 创建匿名函数 None 表示null 值 nonlocal 声明非局部变量 not 逻辑运算符 or 逻辑运算符 pass null 语句,一条什么都不做的语句 raise 产生异常 return 退出函数并返回值 True 布尔值,比较运算的结果...
in the same line, the Python interpreter creates a new object, then references the second variable at the same time. If you do it on separate lines, it doesn't "know" that there's already "wtf!" as an object (because "wtf!" is not implicitly interned as per the facts mentioned abov...
if my_variable is None:print("This variable is None.")```这里有一个新一代的博客平台【WRITE-...
将分类变量转换为数值变量 一些机器学习模型要求变量采用数值格式。这需要先将分类变量转换为数值变量。同时，你也可以保留分类变量，以便进行数据可视化。def convert_cat2num(df):# Convert categorical variable to numerical variable num_encode = {'col_1' : {'YES':1, 'NO':0}, 'col_2' : {'...
n - 1. This is useful if you areconcatenating objects where the concatenation axis does not havemeaningful indexing information. Note the index values on the otheraxes are still respected in the join.keys : sequence, default NoneIf multiple levels passed, should contain tuples. Constructhierarchic...
The next best way of executing Nuitka bare that is from a source checkout or archive, with no environment variable changes, most noteworthy, you do not have to mess with PYTHONPATH at all for Nuitka. You just execute the nuitka and nuitka-run scripts directly without any changes to the en...