The 10 Common Python Development Mistakes and How to Fix Them

The 10 Common Python Development Mistakes and How to Fix Them — Latitude Technolabs

Every developer knows that Python is easy to learn language with various types of use. Most large industries use Python. Many developers know Python very well, but they create very common mistakes that can create huge problems in app development. One common mistake can ruin the whole code, so developers should be well focused on small elements programming and its functions in python programming.

During app development, expert and experienced developers also make common mistakes. Sometimes, mistakes are very tiny that it is nearly impossible to find a mistake, so they write a new code. So, it consumes more time, rises cost, and possibly damages brand reputation, If you want to not happen with you, you can read the whole article, and you can hire python developer for stress-free app development.

Here is the list of the top 10 mistakes made by python developers and how to fix them.

  1. Incorrectly Using Class Variables

In python programming, class variables are like dictionaries, and it is connected to method resolution order (MRO). In the below image, we have an X value of 1, so all classes will give answer 1.

Now, if we put B.x = 2 then

If we put A.x = 3, then the output will be 3 of C.x too.

Now, the question is why the C.x value also changed? Why make changes to A.x and B.x only. We have seen that variables follow MRO. Here, “X” is not in Class C; it will look up in base class. We can say that C doesn’t have any property of X. so that it will reference from A.x. It causes many problems if not handled not correctly. If you are still stuck in this problem, you can hire python developer.

2. Incorrectly Using the ‘’init’’ Method

“‘ init” is a limited program in Python. “Init” is used as a constructor; that’s why it’s termed object-oriented terminology. “init” arrives when Python puts or distributes memory to the new class. This process is used when the object is produced from class. But the mistake is when the object is created, it allows the class to save attributes of the class.

The main work is to put values of instance members for the class object. But the method diversifies the user from the original work to a different one. This error can be fatal.

3. Module Naming In Python Library

Python is famous for its module library. It has various types of libraries in it. But at a time, a python developer may run into a name clash between your module name and the module with the standard library. The standard library is inbuilt.

For example, if you are importing a library but mistakenly import a standard library because python standard library name and the library you want to import are the same. It is the point when an error starts to happen, but you can take care of it easily by changing the name of the module.

4. Misused Expressions

Python allows it to recognize that function is arbitrary by giving it the default value. So, an error can quickly happen if the default value is changeable.

Here, the main confusion is that the optional argument will stick with the default expression, and the function will declare without giving a value for the optional argument.

5. Lack of Understanding of Python Scope

Python scope is based on the LEGB rule; it is the built-in rule.

The following error happens when you perform a variable in scope. But the variable is default set by Python to stay on the local scope, so it looks for any other variable in the external scope. Many developers get UnboundLocalError.

Now, according to the above code, you can see that foo2 failed and foo1 worked. Foo1 is not performing assignment to Ist, but foo2 is remembering “lst += [5]” is” lst= Lst + [5]” but shorter form.

6. Misused The_del_method

“_del_” is used as a destructor. It can be used as a parameter, and it is executed after the program’s end.

For example, the below code is in filename “”.

But you tried to do the same with the file named

After this, you will see an error, Attribute Error exception.

This error occurs because the global variable is attached to “NONE” when the moderator shuts down. So, _del_ is used, and it will set to NONE.

To solve this, developers have to practice atexit.register(). What it does is when the program is done with executing, the registered handler is moved before the moderator is isolated.

The above will give a clean and secure method to call any cleaning function after program termination.

7. Wrong Capitals

It is the most common mistake in python development. It happens when you want to access value, but you are unable to access that. In Python, MyVar is different from myvar and MYVAR.

If you type MyVar = 1 and MYVAR =1, both results will differ because Python doesn’t understand “MYVAR”.

It also happens when using class variables and putting the wrong capitals.

8. Incorrect Parameters Set For Exception

Here the issue is that the statement does not accept the list of exceptions.

In Python, 2.x, the “except’’ exception” is used to connect the exception to the second parameter specified like “e”. as a result, the error “Index Error” exception is not detected by the “except” statement. The exception ends up bounding to “Index Error”.

The solution is:

The except statement has to specify the first parameter, which has all exceptions to be detected.

9. Forgetting To Turn Off Iteration While Editing A List

It is an obvious problem that python developers do. While iteration is on, don’t delete the item from a list or array. This common mistake is made unknowingly.

But there is the solution; Python has promising paradigms that, if appropriately used, can save time, the code will be error-free and straightforward.

The benefit of this one is fewer chances of accidental deletion of an array or an item from the list. It is sometimes a very frustrating problem; if you are still stuck, you can hire python developer.

10. Lack Of Understanding Of Using “Equality”

It is a widespread mistake made by python developers by substituting “is” for “equality” while connecting to integers. But Python uses cache integers, so they do not get info about this.

Example 1: we have got “sim” and “add,” and each has two integers. Now, we are equating it with the “==” operator. The values will be the same in the result but respond as ‘’true.’’ If we add the “is” operator, the result comes out the same. It happens because Python has made the same address for both.

Example 2: We will use long integers, but Python gets integers between -5 to 256. Now, if we add the “is” operator, the result will be not the same. Most of the time, this problem is fixed quickly, but sometimes if you need other hands to solve it more quickly, you can hire python developer.

Final words

As you saw above, mistakes are just of one character, and the whole code drastically changes, some common mistakes are easy to correct but hard to find, and some are both easy to fix and find. By reading the above topic, you will now make correct solutions for your python development common mistakes.

If you are stuck somewhere in challenging problems or want to make a python application, you could hire python developer, we at Latitude Technolabs have experts ready to take the challenge.

Latitude Technolabs Pvt. Ltd. is a leading service provider with extensive experience in providing IT outsourcing services to enterprises across the globe.