What is function call in Python?
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 Show 2 minute read • Python 3.7—3.10 Watch as video 02:17
Sign in to your Python Morsels account to save your screencast settings. Don't have an account yet? Sign up here. What are functions and how can we use them? Calling a functionLet's use a function that's built into Python: the built-in sum function. If we type sum and hit the Enter key, we'll see what the variable sum points to: >>> numbers = [2, 1, 3, 4, 7, 11, 18]
>>> sum
We're not actually using the function here, we're referring to the function object that the variable sum points to. To use this function, we need to put parentheses after it. Putting parenthesis after a function will call the function. >>> sum()
Traceback (most recent call last):
File " When calling this function we got an error because the sum function requires at least one argument but we didn't pass it any arguments. To use the sum function we have to pass it an iterable of numbers as an argument. Arguments and return valuesTo pass an argument to a function, you put the argument inside the parentheses when calling the function. Arguments are basically the inputs to a function. Functions have inputs (as arguments) and an output as a return value. The integer 46 is the return value of this function: We saw 46 printed out at the Python REPL, but this sum function didn't actually print 46, it returned 46. If we put this function call on the right-hand side of an = sign, we can assign the variable total to whatever the return value of calling sum with numbers was (in this case, it was 46). >>> total = sum(numbers) >>> total 46 The default return value is NoneNot all functions have returned values. For example, the print function doesn't have a return value. If we assign a variable to the return value of a print call: >>> name = print("Trey") Trey We'll see text (Trey) printed out, but we'll also see that the variable name is None: >>> name >>> print(name) None None is a special value that basically means this function doesn't have a return value. In Python, we typically assume that functions either perform some action or return something, but not both. The print function performs an action (it prints something to the screen) whereas the sum function returns a value. SummaryTo use functions in Python, you write the function name (or the variable that points to the function object) followed by parentheses (to call the function). If that function accepts arguments (as most functions do), then you'll pass the arguments inside the parentheses as you call the function. If that function has a return value, you can capture that return value into a variable or pass that return value straight into another function call. Series: FunctionsPython, like many programming languages, has functions. A function is a block of code you can call to run that code. Python's functions have a lot of "wait I didn't know that" features. Functions can define default argument values, functions can be called with keyword arguments, and functions can be written to accept any number of arguments. To track your progress on this Python Morsels topic trail, sign in or sign up. ✕ ↑ Concepts Beyond Intro to Python Intro to Python courses often skip over some fundamental Python concepts. Sign up below and I'll share ideas new Pythonistas often overlook. What is function call in Python with example?Function Calling in Python
Once a function is created in Python, we can call it by writing function_name() itself or another function/ nested function. Following is the syntax for calling a function. Syntax: def function_name(): Statement1.
What is a function call?A function call is an expression containing the function name followed by the function call operator, () . If the function has been defined to receive parameters, the values that are to be sent into the function are listed inside the parentheses of the function call operator.
What is call function in Python class?__call__ in Python
The __call__ method enables Python programmers to write classes where the instances behave like functions and can be called like a function. When the instance is called as a function; if this method is defined, x(arg1, arg2, ...) is a shorthand for x.
What is calling and called function in Python?A stack data structure is used during the execution of the function calls. Whenever a function is invoked then the calling function is pushed into the stack and called function is executed. When the called function completes its execution and returns then the calling function is popped from the stack and executed.
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