os.getenv() in Python returns the value of the environment variable key if it exists, otherwise it returns the default.
Syntax: os.getenv (key, default = None)
Parameters:
key: string denoting the name of environment variable
default (optional): string denoting the default value in case key does not exists. If omitted default is set to ’None’.
Return Type: This method returns a string that denotes the value of the environment variable key. In case key does not exists it returns the value of default parameter.
Code # 1: using the os.getenv () method
| # Python program to explain the os.getenv () method
# import of the os module import os
# Get the value & # 39; HOME & # 39;
# environment variable key = ’HOME’ value = os.getenv (key)
# You enter the value & # 39; HOME & # 39;
# environment variable print ( "Value of’ HOME’ environment variable: " , value)
# Get the value & # 39; JAVA_HOME & # 39;
# environment variable key = ’JAVA_HOME’ value = os.getenv (key)
# Print the value & # 39; JAVA_HOME & # 39;
# environment variable print ( "Value of’ JAVA_HOME’ environment variable: " , value) |
Output:
Value of ’HOME’ environment variable: / home / ihritik Value of’ JAVA_HOME’ environment variable: /opt/jdk-10.0.1
Code # 2: if the key does not exist
| # Python program to explain the os.getenv () method
# import of the os module import os
# Get home value
# environment variable key = ’home’ value = < code class = "plain"> os.getenv (key)
# Print the value & # 39; home & # 39;
# environment variable print ( "Value of’ home’ environment variable: " , value) |
Exit:
Value of ’home ’environment variable: None
Code # 3: explicitly specifying the default
| # Python program to explain the os.getenv () method
# module import os import os
# Get home value
# environment variable key = ’home’ value = os.getenv (key, "value does not exist" )
# Print the value & # 39; home & # 39;
# environment variable print ( "Value of’ home’ environment variable: " , value) |
Exit:
Value of ’home’ environment variable: value does not exist
