How to access environment variable values in Python? Environment variables are a way to store configuration values that can be accessed by applications and scripts without hardcoding them into the code. Python provides several methods for accessing environment variables are os.environ, os.getenv(), and the python-dotenv package.
In this article, we will explore these different methods and provide code examples to help you learn how to access environment variables in Python. Let’s get started!
1. Quick Examples – Access Environment Variable Values
These examples provide a high-level overview of how to access environment variables using os.environ and os.getenv(). We will discuss each of these methods in more detail and provide examples.
# Quick examples
import os
# Accessing environment variable using os.environ
database_url = os.environ.get(‘DATABASE_URL’)
if database_url is not None:
print(f”Database URL: {database_url}”)
else:
print(“DATABASE_URL environment variable not found”)
# Accessing environment variable using os.getenv()
api_key = os.getenv(‘API_KEY’)
if api_key is not None:
print(f”API key: {api_key}”)
else:
print(“API_KEY environment variable not found”)
2. Access Environment Variables using os.environ
os.environ is a dictionary-like object that contains all the environment variables set on the system. You can use it to access individual environment variables by their name, or iterate over all environment variables.
To access an individual environment variable using os.environ, you can use the get() method with the name of the variable as the argument. If the variable exists, get() will return its value.
# Get the value of the HOME environment variable
import os
home_dir = os.environ.get(‘Python’)
print(home_dir)
If the variable doesn’t exist, get() will return None. You can also iterate over all environment variables using the items() method. This returns a list of key-value pairs, where each key is the name of an environment variable and each value is its corresponding value.
import os
# Iterate over all environment variables
for key, value in os.environ.items():
print(f”{key}={value}”)
On my laptop, I get the below output (it’s a partial output).
3. os.getenv() – Access Environment Variables Values
The os.getenv() method provided by the os module that allows you to retrieve the value of a specific environment variable by name. It works in a similar way to os.environ.get().
# Get the value of the python HOME
import os
home_dir = os.getenv(‘Python’)
print(home_dir)
With using os.getenv() we can also specify the default value, so if the value doesn’t exist it will give us that default value.
# Use default value if it doesn’t exist
import os
my_setting = os.getenv(‘MY_SETTING’, ‘default_value’)
print(my_setting)
4. python-dotenv package – To Access Environment Variables
This is a bit advanced method, where you will need to install a third-party package. The python-dotenv package provides a convenient way to load environment variables from a file and make them available to your Python script.
This can be useful if you have a large number of environment variables or if you need to manage them across different environments, such as development, testing, and production.
You need to first install the package:
# Install python-dotenv
pip install python-dotenv
Once you’ve installed the package, you can create a new .env file in your project directory and define your environment variables in the format NAME=VALUE.
For example: Make sure you create a file with name.env.
DB_HOST=localhost
DB_PORT=5432
DB_NAME=mydatabase
DB_USER=myuser
DB_PASSWORD=mypassword
You can use the load_dotenv() function from the dotenv module to load the environment variables from the .env file into your Python script:
from dotenv import load_dotenv
import os
# Load the environment variables from the .env file
load_dotenv()
# Get the value of the DB_HOST environment variable
db_host = os.environ[‘DB_HOST’]
print(db_host)
Summary and Conclusion
We have discussed several methods to access environment variable values in Python, including using os.environ, os.getenv(), and python-dotenv. If you have any questions or comments, feel free to leave them below.
Happy coding!
How to access environment variable values in Python? Environment variables are a way to store configuration values that can be accessed by applications and scripts without hardcoding them into the code. Python provides several methods for accessing environment variables are os.environ, os.getenv(), and the python-dotenv package. In this article, we will explore these different methods Read More Python, Python Tutorial