## How to get a list of parameter names inside Python function?

Updated on 27-Mar-2023 19:36:05
To extract the number and names of the arguments from a function or function[something] to return ("arg1", "arg2"), we use the inspect module. The given code is written as follows using inspect module to find the parameters inside the functions aMethod and foo. Example import inspect def aMethod(arg1, arg2): pass print(inspect.getargspec(aMethod)) def foo(a, b, c=4, *arglist, **keywords): pass print(inspect.getargspec(foo)) Output ArgSpec(args=['arg1', 'arg2'], varargs=None, keywords=None, defaults=None) ArgSpec(args=['a', 'b', 'c'], varargs='arglist', keywords='keywords', defaults=(4, )) To get a list of parameter names inside a Python function, you can use the inspect module. This module ... Read More

## How can we create recursive functions in Python?

Updated on 27-Mar-2023 19:15:25
Recursion is a programming technique, in which a function calls itself one or more times in its body. Usually, it is returning the return value of this function call. If a function definition follows recursion, we call this function a recursive function. A recursive function has to be terminated before it can be used in a program. It terminates, if, with every recursive call, the solution of the problem becomes smaller and moves towards a base case, where the problem can be solved without further recursion. A recursion can lead to an infinite loop, if the base case is ... Read More

## How can we overload a Python function?

Updated on 27-Mar-2023 18:55:19
In Python, you can define a method in such a way that there are multiple ways to call it. Depending on the function definition, it can be called with zero, one, two or more parameters. This is known as method overloading. . In the given code, there is a class with one method, sayHello(). We rewrite as shown below. The first parameter of this method is set to None, which gives us the option to call it with or without a parameter. An object is created based on the class, and we call its method using zero ... Read More

## How to retrieve source code from Python objects?

Updated on 27-Mar-2023 18:40:16
Using the inspect module, you can retrieve the source code of a Python function, method, class, or module. The following example demonstrates how to retrieve a function's source code: Example import inspect def my_function(x, y): return x + y source_code = inspect.getsource(my_function) print(source_code) Output def my_function(x, y): return x + y This code defines a simple function my function that accepts two arguments and returns the sum of those arguments. We then retrieve the source code of the my function function using the inspect.getsource ... Read More

## How can we define a Python function at runtime?

Updated on 27-Mar-2023 18:21:57
We can define a python function and execute it at runtime by importing the types module and using its function types.FunctionType() as follows This code works at the python prompt as shown. First we import the types module. Then we run the command dynf=…; then we call the function dynf() to get the output as shown import types dynf = types.FunctionType(compile('print("Really Works")', 'dyn.py', 'exec'), {}) dynf() Output Really Works Defining a Python function at runtime can be useful in a variety of situations, such as when you need to ... Read More

## How to write recursive Python Function to find factorial?

Updated on 27-Mar-2023 18:19:21
Factorial of a number is the product of all the positive integers from 1 to that number. For example, the factorial of 4 is 4*3*2*1 = 24. To find the factorial of a number using recursive Python function, we can define a function that calls itself with a smaller input until it reaches the base case, which is the factorial of 1, which is 1. Here is the code to find the factorial of a number using recursive Python function: def factorial(n): if n == 1: ... Read More

## Are Python functions objects?

Updated on 27-Mar-2023 18:18:20
Python creates function objects for you when you use a def statement, or when you use a lambda expression: We can assign attributes to the function object and retrieve them as follows Example def foo(): pass foo.score = 20 print(type(foo)) print(foo.score) print(type(lambda x:x)) Output 20 Yes, python functions are full objects. They can have attributes and methods like objects. The functions can have data variables and even functions written inside of them.  Indeed Python functions are objects. This means that they can be assigned to variables, passed as arguments to other ... Read More

## How to remove all trailing whitespace of string in Python?

Updated on 27-Mar-2023 18:17:45
Any character or group of characters that depicts horizontal or vertical space is known as whitespace. A whitespace character usually takes up space on a page even though it does not correspond to any visible mark when it is rendered. Pressing the spacebar will allow you to enter a whitespace character. On many keyboards, the Tab key can also be used to enter horizontal whitespace, although the length of the space may vary. Any spaces or tabs that follow the final non-whitespace character on the line until the newline are considered trailing whitespace. Whitespace in Python Whitespace is a ... Read More

## What is PYTHONPATH environment variable in Python?

Updated on 27-Mar-2023 18:16:27
In Python, PYTHONPATH is an environment variable that specifies a list of directories to search for Python modules when importing them. When you import a module in Python, Python looks for the module in the directories specified in sys.path, which is a list of directories that includes the current working directory and directories specified in PYTHONPATH. PYTHONPATH is an environment variable which you can set to add additional directories where python will look for modules and packages. For most installations, you should not set these variables since they are not needed for Python to run. Python knows where to find ... Read More

## How to set Python environment variable PYTHONPATH on Linux?

Updated on 27-Mar-2023 18:15:41
To set the PYTHONPATH environment variable on Linux, follow these steps: Open a terminal window on your Linux system. Determine the path to your Python module or package. For example, suppose you have a Python module named mymodule located in the /home/user/myproject folder. Set the PYTHONPATH environment variable to the path of your module or package using the following command: $export PYTHONPATH=/home/user/myproject:$PYTHONPATH This command sets the PYTHONPATH environment variable to /home/user/myproject and also includes the previous value of PYTHONPATH in case it was already set. Note that the path should be separated by a colon (:) on Linux. ... Read More