What are the three places where Python looks for packages/modules when importing them?
When importing packages or modules in Python, the interpreter looks for them in three specific places: the built-in modules, the current working directory, and the directories listed in the sys.path variable.
The first place Python looks for packages or modules is in the built-in modules. These modules are part of the Python standard library and are available for use without the need for any additional installation or configuration. They provide a wide range of functionality, including file I/O, networking, regular expressions, and more. Examples of built-in modules include math, os, datetime, and random.
The second place Python looks for packages or modules is in the current working directory. When executing a Python script, the interpreter sets the current working directory to the location of the script file. If the package or module being imported is located in the same directory as the script, Python will find and import it without any issues. For example, if we have a script called "my_script.py" and a module called "my_module.py" in the same directory, we can import the module in the script using the statement "import my_module".
The third and final place Python looks for packages or modules is in the directories listed in the sys.path variable. The sys.path variable is a list of directory names where Python looks for modules when importing. By default, it includes the current working directory and the directories specified in the PYTHONPATH environment variable. Additionally, it includes the directories where the standard library modules are installed. This allows for the use of modules located in different directories on the system.
To add a custom directory to the sys.path variable, you can use the sys.path.append() method. For example, if we have a directory called "my_modules" containing a module called "my_module.py", we can add it to the sys.path and import the module using the following code:
python
import sys
sys.path.append('/path/to/my_modules')
import my_module
In this example, we first import the sys module and then use the sys.path.append() method to add the directory "/path/to/my_modules" to the sys.path. After that, we can import the module "my_module" as usual.
When importing packages or modules in Python, the interpreter looks for them in the built-in modules, the current working directory, and the directories listed in the sys.path variable. Understanding these import locations is important for managing dependencies and ensuring that the required modules are available for use in your Python programs.
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