local variable referenced before assignment python

Print ("Initial num1=", NUM1) Fun () Print ("num1= after running function", NUM1) Operation Result:You can see that after modifying the global variable inside the function, the result of the modification is invalid when the function is executed, and the global variable is not affectedLook again:DEMO3: def fun (): num1*=2 print ("Inside function modified num1=", NUM1) num1=1 Print ("Init

The variable names in Python are parsed at compile time, in other words, at compile time (that is, when the interactive console enters the code or import file), Python has decided whether a variable should be a local variable or a

called LOAD_FAST , because the local variables are read from a called fastlocals array, so the name is called (I guess). So the main character comes, we have to focus on this, because this is really very interesting. Python function execution The construction and operation of Python functions, said the complexity is not complex, said simple is not simple, becaus

In this section, we'll expand the variable assignment in detail.1. Below we give examples of various assignmentsAnint=12anfloat=2.2anstr= ' string ' alist=[' a ', ' a ', ' a ']anarray= (all-in-all) Amap={1: ' A ', 2: ' B ', 3: ' C ',}2. Chained assignment3. Increment assignment, i.e. self-increment or self-reduction, etc.These operators: +=,-=,*=,/=,%=,**=,>>=,X+

In Python, when we make a variable equal to another variable, it does not pass the value to it, but instead directly changes the address to the point. We want to see the address of a variable in memory, which can be viewed by ID (variable). Let's take a look at this interest

This time to bring you a Python variable assignment of the step-by-bit details, the Python variable assignment of attention to what, the following is the actual case, together to see. >>> x = 12>>> y= 13>>> ID (x) >>> ID (y) >>>

This is a creation in Article, where the information may have evolved or changed. Usually write much is python, recently saw a little go, today encountered a problem, and share with you package mainimport "fmt"type student struct { Name string Age int}func pase_student() { m := make(map[string]*student) stus := []student{ {Name: "zhou", Age: 24}, {Name: "li", Age: 23}, {Name: "wang", Age: 22}, } for _, stu := ra

1. Assigning values to variablesLetters are quoted as strings, not labeled as variable names." Jbzhang " = nameprint="jbz"print(name2)Memory Reclamation: The memory space created, when there is no variable pointing, the memory space will be emptied or deleted directly.Like what:1. Delete directlyAge=21Del age2. Cancel the pointAge=22Age=232.if Statement Implementation guess ageAge_of_princal= + = Int (inpu

Excessive Parameters It is generally impossible to know the parameters of a function at runtime. Another scenario is that a function can operate many objects. What's more, calling your own functions becomes an api provided to available applications. In these cases, python provides two special methods to define function parameters, allowing the function to accept excessive parameters without explicitly declaring parameters. These "extra" parameters are

Python Function Local variable usage instance analysis, python instance analysis This example describes how to use local variables of python functions. Share it with you for your reference. The specific analysis is as follows: Whe

Os.path.basename (PATH): Return file name Os.path.dirname (PATH): Return file path Os.remove (dir) #dir为要删除的文件夹或者文件路径 Os.rmdir (Path) #path要删除的目录的路径. It should be explained that the directory deleted using Os.rmdir must be an empty directory, or the function will fail. Os.path.getmtime (name) # Gets the file modification time Os.stat (path). st_mtime# Gets the modified time of the file Os.stat (path). St_ctime #获取文件修改时间 Os.path.getctime (name) #获取文件的创建时间 Method OneI

[Python] threading local thread small variable testConcept There is a concept called a local variable in a thread. Generally, we lock global variables in multiple threads. Such variables are shared variables, and each thread can read and write variables, in order to keep the

The example in this article describes the Python function local variable usage. Share to everyone for your reference. The specific analysis is as follows: When you declare variables within a function definition, they are not related to other variables with the same name outside the function, that is, the variable name

: object.__setattr__(self, '__dict__', d) Each time before calling the attribute of the local instance, the local will call this method to find the place where it saves the value. D = currentThread (). _ dict _. get (key) is the place where the local_data value is stored. Therefore, when a subthread accesses local_data, it does not obtain the value of loc

Following code explain how ' global ' works in the distinction of global variable and local variable.1var ='Global Variable'2 Print(Var)3 4 deffunc1 ():5var ='Local Variable'6 Print(Var)7 8 defFunc2 ():9 Print(Var)Ten One