Python os getenv

In the python programming language “os.getenv()”, module can return the content of an environment variable’s key if it is present. And if it does not exists, it will return the default value that would probably be “none” or “null”. This is a method that returns the result of an environment variable. An environmental attribute is an extrinsic designated value that depends on the machine. When a global consequence is intended or when an arbitrary system interface calls for an environment variable then it ought to be utilized.

We would learn the significance of environment variables and also how these relate to the currently running python programs. The context in which processes like all python applications are launched includes environment variables. It is made up of a title duo and may always be retrieved, changed, or opcode.

Commonly, these variables are set directly on the command line interface or through shell scripting where we have a startup of the operating system and even software programs, nevertheless can communicate with them. This article will demonstrate what to do to transfer new environment variables and dynamically acquire, modify, and unset existing ones. Finally, we will show you a few alternatives to validate whether an environment variable is true.


The syntax of “os.getenv” has two parameters where first is the “key” part which would belong to a string and the second parameter is “default” for the no existing case.

Example 1: Utilizing the “os.getenv()” Module for Specifying the Explicit of Any Default Parameter.

When a variable is not handed in the defaults field it can be used to set default settings for undefined function arguments. If an argument is absent from a statement, then its outcome is indeterminate. The compiler implements the default value whatever we indicate in this situation. More particularly, we would demonstrate utilizing python well how to read, unset, or even outsource environmental variables.

Let’s start implementing the code example for the module of “os.getenv()” where we imported the “os” library as the compulsory material because the interaction required with the machine system is a must. Then, we created our function with the name “Get_key” and assigned the key value to it “Satellite”.

Now, we applied our “os.getenv()” module in the “Get_Value” function we created so far and assigned that key to the “os.getenv” which is stored in “Get_key” with the statement “The Get Value Doesn’t Exist!”. We used the “print()” function in the last line of “getenv” and provided the print statement of “Get key of ‘Satellite’ Environment Variable:” then called the value of the function “Get_Value”. The code is completed and now we will compile our code and run it to look at the output we will obtain.

After code compilation, we will have this kind of output on the screen that is given here for “os.getenv()”. As the key was absent, it will display the defaulted value and shows that “The Get Value Doesn’t Exist!” for the key provided “Satellite”.

Example 2: Utilizing the “os.getenv()” Module for the Specific Key Whose Existence is Absent.

Now, in this example, we will look at the handling phenomenon of those keys that are not in their present state by the “os,getenv” module. This methodology provides a string that represents the environmental variable to predict. If the initial argument is missing, it would remember its variable values. It is also crucial to note that context variables are typically used by more than just our python program. As a result, we should start taking care when interacting with them so as not to unintentionally damage other programs or any other worse action that could alter the order in which other processes execute.

Let us start implementing by importing the “os” library and then creating the user-defined functions. The function which we have created so far is named “get_key” and assigned the key-specific value of “TOSHIBA”. Now, we created a new function again with the name “get_value” that is much similar to the function we used in the previous example and assigned it the “os.getenv()” function while applying the “os.getenv()” function. In the “get_value”, we assigned “get_key” within the main module of the article. Here now we implied the “print()” function with the simple print statement of “Get key of ‘TOSHIBA’ Environment Variable:” and then called the function of “get_value” in the last within the “print()” function just after the print statement.

After implementation, we will have the statement “Get key of ‘TOSHIBA’ Environment Variable:” with the default value of “None” as our defined key is not present and it would be unable to reach it so it would return “None” on the output. If the key could be present, then the case might be different.

Example 3: Utilizing the “os.getenv()” Module to Obtain the Environment of Any Get Key File.

This area has been covered in the first two parts but we’ll also show you a couple of other techniques for determining whether an environment variable is present. We can use the “os.getenv()” to find that for reaching or having the environment of any specific key file while passing it into the string. This would help us to find out the path environment of our file of the key that we are willing for.

Let us start the implementation of the code of the last example we used for “os.getenv()” which will import the “os” library before setting up the respective code. Then, we created our function name “GET_key” and assigned it the key name “Desktop1”. After assigning and function creation, we created a new function named “GET_value” where we applied the “os.getenv()” module and assigned it the function “GET_key” by calling.

Now, we used the “print()” function with the print statement “Value of ‘Desktop1’ Environment Variable:” and called “GET_value” within the “print()” function. Here, we will again create a new function named “GET_key1” and assign “PythonA_Desktop1”. A new function has been created again of the name “GET_value1” and applied the “os.getenv()” module for reaching the environment and called the function of value “GET_key1”. At the last line of code, we will again use the “print()” function with the print statement of “Value of ‘Python_Desktop1’ Environment Variable:” and call the “GET_value1” function in the “print()” function after the print statement.

The output will display the environment of the path of the keys we provided in the code of “os.getenv”. In the first line of output, it will display the print statement along with the path and user name of our operating system. And the second line will also present the print statement we provide in the code for the key “Python_Desktop1” along with the location environmental path we obtain by the “getenv” module as the exact reaching environment.


Our article covers the topic of the operating system module of the python language “os.getenv()”. We easily described this topic by using three examples related to the module where the first example covers the explicit specificity of any key file and the second one determines the vanished or absent key file. In the third example, we cover the utilization of the “os.getenv” module for elaborating and finding out the environmental location or path of the specified key.

About the author

Aqsa Yasin

I am a self-motivated information technology professional with a passion for writing. I am a technical writer and love to write for all Linux flavors and Windows.