How To Fix KeyError In Python?

Do you know what is KeyError in Python programming language? Have you ever thought about what mistake is referred to as the KeyError in Python programming language? If you’re curious to know about the KeyError and need help with Python homework then this article is for you.

W need to know the basic of it by discussing some daily life examples. It will help to know what does KeyError mean in python programming language.

Real Life Example:

Suppose, you have a special friend in your life. Your friend is not mature enough. Sometimes, he asks you to help in such situations which is very childish. Any person who has common sense can able to resolve the such situation. But your friend can’t able to do so. He always comes to you for help. One day, that friend comes to you & asks to find out a word from the dictionary. He has had some issues finding the word.

Now, he handed over a Hindi-to-Bengali dictionary to you & ask you to find out the meaning of an English word. The situation is very childish, but as I have said earlier, your friend doesn’t have the common sense to judge. So, what will you do there?

You have to tell your friend that from a Hindi to Bengali dictionary, an English word can’t be found. For that purpose, he needs to have an English-to-Bengali or English-to-Hindi dictionary. The same situation arrives in the KeyError in Python programming language. Programmers try to find out a specific element from a list that is not present there.

And for that reason, the whole program stops working. It will be clearer to you when we discuss what does keyerror mean in python programming language. But for the time being, we can assume that the background & basic is clear for KeyError in Python programming language. But before we start writing about what is KeyError in Python programming language, we need to know about the Dictionary concept in Python programming language.

Also, if you’re curious to know about errors in other programming language like C then you can check out our article on “What Are Errors In C Programming?“

What Is Dictionary In Python Programming Language? Read Below

It is necessary to discuss the Dictionary concept in the Python programming language before we move towards the discussion about what is KeyError in Python programming language. A dictionary is a special Data Structure present in the Python programming language. Programmers can able to store different types of data types inside the dictionary. They can able to store an integer data type along with the String data type. Programmers need to use curly braces to mark the boundary of the dictionary.

There are two types of an element present in the dictionary in Python programming language. These elements are going to help to find out what does keyerror mean in python programming language. One of the elements is known as the Value & another will be known as the Key. These elements are separated with the help of that ‘:’ symbol. The element on the left side will be known as the Key. And the element on the right side is known as the Value. Using the Key, programmers can find the value & vice versa. For these reasons, the Dictionary is used widely in Python programming language.

What Is KeyError In Python Programming Language? Get To Know

Now, after knowing Dictionary in Python programming language, we need to discuss what does KeyError mean in Python programming language. As the name suggests, the problem is related to the Key element in the dictionary. If we simply decode the name, we will find some signal of errors with the Key element. Now, you are going to find out some similarities with the above-mentioned example. You need to pay attention now as we are going to discuss what is KeyError in Python programming language.

Often time, when programmers are developing a large project, such issues happen. You don’t need to think that, it is an issue that comes from the machine. It is a silly mistake that needs to be paid a high amount in the future. In a big project, programmers developed different dictionaries in the Python programming language at the same time.

Also, they put some values & keys to it. Now, when developing the project, sometimes they forget which key or value is assigned to which dictionary. And it is a quite difficult job to find out the respective keys from the dictionary.

So, programmers often try to access the key which is not at all present in the dictionary. It is the same situation that your friend tries to. That is why; we discussed the daily life example before help you understand what is KeyError in Python programming language. As a result, the key will not be accessible from the dictionary. And the program rejects to execute.

What Is The Mistake In KeyError In Python Programming Language?

Now, programmers need to roam the entire project to find out a simple mistake. This mistake is known as the KeyError in Python programming language. Hope, you have now understood what does keyerror mean in python programming language.

Also, if you are curious to know about the concept of  type conversion, then you can read our article on “What is Type Conversion In Python?”

What Is The Example Of KeyError In Python Programming Language?

Now, after discussing what is KeyError in Python programming language, we need to discuss one example of it. It will help you to understand & mark the mistake. It will also help to know what does keyerror mean in python programming language.

Here, we have taken one dictionary in Python programming language. We have also provided some values & keys to the dictionary. And now, it is ready to be printed. Now, instead of printing the key which is present in the dictionary, we are printing a random one.

The key ‘C’ is not present in the dictionary. And we are trying to fetch the value of this key. We are trying to print it. As a result, it will give an error. It is the KeyError in Python programming language.

Example:

zap = {'Python': 1, 'Java': 2, 'C++': 3} # Taking One Dictionary With Values & Keys

print(zap['C']) # Print The Value Of An Absent Key

Let us try to find out the output of the above code. It will help to understand the error that comes with the KeyError in Python programming language.

Output:

What Are The Disadvantages Of KeyError In Python Programming Language?

Now, we have seen what is KeyError in Python programming language & as well as an example of it. We can now easily find out the solution of what does keyerror mean in python programming language. Now, it is time to know some disadvantages of the KeyError in Python programming language. It will help to provide more importance to the topic.

Let us try to make a list of disadvantages of KeyError in Python programming language. They are the following:

• KeyError in Python creates a mess in big projects where dictionaries play an important role. In a large dictionary, it is hard to remember all the names of the keys. In such cases, this issue arises.
• It causes a certain breakdown of the compilation process of the Python programming language. Hence it is a big issue.
• Programmers need to face difficulties to find out the issue right in the position of a big project. So, programmers need to be very careful.

What Are The Methods To Fix KeyError In Python Programming Language?

Now after knowing what is KeyError in Python programming language, we are going to write about the methods to fix KeyError in Python programming language. There are mainly three types of methods present to resolve the issue. Some of the issues are quite simple but they can take a long time for a big dictionary. In other cases, some of them are very easy to implement.

Let us try to make a list of methods that will resolve the issue KeyError in Python programming language easily. The methods are the following:

• Using Conditional Statement
• Using Get() Function
• Using Try Block.

After clearing what does keyerror mean in python programming language, let us try to know about each of them one by one.

Method 1: Using Conditional Statement:

Here, we are going to use conditional statements in Python programming. The conditional statement means the If-Else statement. If the key is present in the program, it will be printed. Else, they will be printed the message & move ahead. In this way, the program will not terminate by itself.

Here, we have first taken one dictionary. We have also provided some values & keys to the dictionary. Now, we are using the If statement to check the presence of the key. If the key is present, the value will be printed. Otherwise, the statement will be printed. In this case, as the key is not present in the programming, the statement will be printed. To understand this, you need to clarify what does keyerror mean in python programming language.

Example:

zap = {'Python': 1, 'Java': 2, 'C++': 3} # Taking One Dictionary With Values & Keys

if 'C' in zap: # Condition To Check Presence Of The Key

  print(zap['C']) # Priniting The Value Of Key

else:

  print('There Is No Such Key') # Otherwise, Print The Statement

Let us try to find out the output of the above code. It will help to understand the method to fix KeyError in Python programming language using the conditional statement.

Output:

Method 2: Using Get Function:

Get is an inbuilt function provided by the Python programming language. Here, the original value of the shared item will be provided. Else, the default statement will be printed in the program. It is a relatively small program that the previous one. And it doesn’t take a long time to complete.

Here again, we have first taken one dictionary. We have also provided some values & keys to the dictionary. Now, using the get inbuilt function, we are sharing the name of the key & default statement. As the key is not present in the dictionary, the default statement will be printed. To understand this, you need to clarify what is KeyError in Python programming language.

Example:

zap = {'Python': 1, 'Java': 2, 'C++': 3} # Taking One Dictionary With Values & Keys

print(zap.get('C', 'There Is No Such Key')) # Using Get Function To Do Both Tasks Simultaneously

Let us try to find out the output of the above code. It will help to understand the method to fix KeyError in Python programming language using the Get() function.

Output:

Method 3: Using Try Block:

Now, it is the last & most effective method in this case. We all are known about the Try-Catch block in the Java programming language. It is used there to handle programs where possible exceptions can arise. Here, also we will implement that thing. If KeyError in Python programming language happens, it will bypass the issue.

Here, we have to take a dictionary first. Along with that, we have to provide the values & keys to the dictionary. After that, we will implement the Try block & inside that block, we will try to print the value of a key that is absent in the dictionary. Then we will use except & define the KeyError. After that, under that block, we will print the message. And in this way, the program will be completed without providing any issues to the output.

Example:

zap = {'Python': 1, 'Java': 2, 'C++': 3} # Taking One Dictionary With Values & Keys

try: # Try Block To Print The Value

    print(zap['C']) # Printing The Value

except KeyError: # Checking For KeyError

    print('There Is No Such Key') # Otherwise, Print The Statement

Let us try to find out the output of the above code. It will help to understand the method to fix KeyError in Python programming language using the Try block.

Output:

Conclusion:

As we saw, the KeyError in Python programming language is a very important topic.

You need to know all the methods that can be used to fix the KeyError problem in the Python programming language. As you don’t know which method will be useful at some certain place. So, it will be better to have a nice grip on all the methods.

It is advisable to clear the basic concept of the Python programming language. The Dictionary concept should be clear from the beginning. Otherwise, programmers might face difficulties here. Programmers need to clear this concept to easily solve & develop difficult projects in the future.

So, hope you have liked this piece of article. Share your thoughts in the comments section and let us know if we can improve more.

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