How to Create N Variables in Python

Occasionally, you might need to store a list of data points in Python. However, declaring individual variables for each data point can be tedious, especially when dealing with large data sets.

But, Python’s dynamic typing and powerful features make it easy to automate this task. This tutorial will guide you to create N variables dynamically in Python.

Step 1: Getting Started

The simplest way to create a list of variables dynamically is to use a basic for loop or list comprehension. You can store each variable in a list or dictionary for easy access. Here is a simple example:

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amount = 10  
my_variables = {}  
for i in range(amount):  
    my_variables["var_{0}".format(i)] = "Variable {0}".format(i)  
print(my_variables)  

In this code, we create a dictionary and then use a loop to populate it with variables. The variables are named var_0 through var_9, and their values are “Variable 0” through “Variable 9”. When you print ‘my_variables’, you will see these values.

Step 2: Using exec

The exec function in Python provides another method for creating variables dynamically. However, it should be used with care, as it can also introduce security risks if not handled properly. Here’s an example:

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for i in range(10):  
    exec("var_{0} = {0}".format(i))  
print(var_0,var_1,var_2,var_3,var_4,var_5,var_6,var_7,var_8,var_9)  

In this code, we use exec to create new variables var_0 through var_9, setting their values to 0 through 9 respectively. When we print the variables, we can see their assigned values.

Step 3: Using globals

The globals function in Python returns a dictionary representing the current global symbol table, which is always the dictionary of the current module. This is another method for creating variables dynamically. Here’s an example:

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for i in range(10):
    globals()["var_{0}".format(i)] = i
print(var_0,var_1,var_2,var_3,var_4,var_5,var_6,var_7,var_8,var_9)

In this code, we use globals to create new variables in the global scope and assign their values.

Full Code:

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#Method 1
amount = 10
my_variables = {}
for i in range(amount):
     my_variables["var_{0}".format(i)] = "Variable {0}".format(i)
print(my_variables)
 
#Method 2
for i in range(10):
     exec("var_{0} = {0}".format(i))
print(var_0,var_1,var_2,var_3,var_4,var_5,var_6,var_7,var_8,var_9)
 
#Method 3
for i in range(10):
    globals()["var_{0}".format(i)] = i
print(var_0,var_1,var_2,var_3,var_4,var_5,var_6,var_7,var_8,var_9)

Conclusion

And that’s how you create N variables dynamically in Python! Please be aware that, in practice, this is rarely the best solution – it’s usually better to use a data structure like a list or dictionary. However, knowing how to create N variables dynamically can be handy for certain use cases and for understanding more about how Python works.