MemoryError Raised when an operation runs out of memory. NameError Raised when a variable is not found in the local or global scope. NotImplementedError Raised by abstract methods. OSError Raised when a system
python缩进来表示代码块,不使用大括号 {} 。 缩进的空格数是可变的,但是同一个代码块的语句必须包含相同的缩进空格数。 4、数字(Number)类型 python中数字有四种类型:整数、布尔型、浮点数和复数。 int(整数), 如 1 bool(布尔), 如 True float(浮点数), 如 1.23、3E-2 complex(复数), 如 1 + 2j、 ...
变量名应该遵循一定的命名约定,采用驼峰命名法或下划线命名法:驼峰命名法指的是将每个单词的首字母大写,单词之间不使用下划线,例如myVariableName;下划线命名法指的是使用小写字母和下划线来分隔单词,例如my_variable_name。在Python中,推荐使用下划线命名法(也称为蛇形命名法) 变量名只能包含字母、数字和下划线_,不能以...
# 先转换成浮点数,再转换为整型 i = int(float("3.14")) # 或者 i = int(eval("3.14")) 18. UnboundLocalError: local variable 'x' referenced before assignment 试图访问一个不存在的本地变量。 x = 1 def foo(): x = x + 1 # x在foo()这个范围内并没有提前赋值,相当于还不存在。 print(x...
我们从生成器开始,然后访问上下文管理器和协程,包括具有挑战性但功能强大的新yield from语法。第十八章包含一个重要的示例,在一个简单但功能齐全的语言解释器中使用模式匹配。第十九章,"Python 中的并发模型"是一个新章节,概述了 Python 中并发和并行处理的替代方案、它们的局限性以及软件架构如何允许 Python 在网络...
the variable x1 has been removed.Example 2: Remove Multiple Columns from pandas DataFrame by NameExample 2 shows how to drop several variables from a pandas DataFrame in Python based on the names of these variables.For this, we have to specify a list of column names within the drop function...
Remove ads Memory Management: From Hardware to Software Memory management is the process by which applications read and write data. A memory manager determines where to put an application’s data. Since there’s a finite chunk of memory, like the pages in our book analogy, the manager has to...
(envValue=ZTP_STATUS_END, ops_conn=None): """Set the ZTP process status. input: envValue int Environment variable value, which can be true or false output: ret int Operation result """ logging.info("Set the value of envZtpStatus to {} .".format(envValue)) if envValue not in ['...
Variable name "st" doesn't conform to snake_case naming style (invalid-name) 修改成 Missing module docstring (missing-module-docstring) 添加模块的docstring文档说明即可 C0103: Constant name "%s" doesn't conform to snake_case naming style ...
from datetimeimportdatetimeimportmatplotlib.pylabasplt 代码语言:javascript 代码运行次数:0 运行 AI代码解释 # 读取数据,pd.read_csv默认生成DataFrame对象,需将其转换成Series对象 df=pd.read_csv('AirPassengers.csv',encoding='utf-8',index_col='date')df.index=pd.to_datetime(df.index)# 将字符串索引转...