How to Add a String to a Variable Name in Python

In today’s article, we will discuss how to append a string (or any text) to a variable name in Python. This is an essential aspect of dynamic programming, especially while dealing with large data sets, where managing numerous variables can get tricky and labor-intensive.

Step 1: Understanding the Concept

First and foremost, it’s important to understand that variable names in Python (or any programming language for that matter) are not strings. Therefore, adding a string to them will not directly work. Would it be nice if we could just write “var” + “1” to get a new variable var1? Unfortunately, that’s not how it works in Python.

Step 2: Creating Variable Names Dynamically

Python offers a more controlled way to add string dynamically to a variable name using its built-in function exec(). The exec() function is a Python built-in function that dynamically executes the Python program which can include a string or object code.

Here is an example:

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base_name = 'var'
for i in range(5):
  exec("%s%d = %d" % (base_name, i, i*2))

In the above code, we start with a base variable name ‘var’. We use a loop to create 5 variables (var0, var1, …, var4), having values (0, 2, 4, 6, 8). Here, the exec() function has dynamically executed the Python program.

Step 3: Verifying the Variables

Finally, let’s verify if our new variables have been created correctly:

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for i in range(5):
  exec("print(%s%d)" % (base_name, i))

Let’s see what we get:

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2
4
6
8

This confirms the correct creation and assignment of our new variables.

Here is the Full Code

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base_name = 'var'
for i in range(5):
  exec("%s%d = %d" % (base_name, i, i*2))
 
for i in range(5):
  exec("print(%s%d)" % (base_name, i))

Conclusion

Adding a string to a variable name in Python can be a useful feature when dealing with numerous variables in data-intensive tasks. It allows you to create and manipulate variables dynamically, resulting in cleaner and more manageable code.

Remember to use this feature judiciously, as it’s powerful but can also lead to more complex code if not well handled.