A function
id a block of statement in which instruction is given to perform a particular
task. It provides code reusability. They provide better modularity of the
program. Python has a number of built in function and we can have user defined
function also in it. Functions
in Python, we have three parts:
1) Function
Declaration
2)
Definition
3) Calling
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| Functions in Python |
Function
declaration is done first before giving the code to be performed. There is some
rule for function definition
1) There is
a keyword def followed by the function name and ()
2) The
argument and parameter are given in ()
3) Colon:
will be used for indentation
4) The first
statement of the function is an optional statement which the documentation
string or the docstring
5) The
return statement exit the function and the return without argument will be
similar to return none
Function
definition in Python
Programming will be code which we have to run to get the required
output. Function
calling can be done in two ways
1) Call by
value
2) Call by
reference
1) Function
with no argument and no return value
2) Function
with no argument and with return value
3) Function
with argument and no return value
4) Function
with argument and with return value
Function Argument:
1)
Keyworded
2) Default
3) Variable
length argument
4) Required
Argument
The Anonymous Functions:
These
functions are called anonymous because they are not declared in the standard
manner by using the def keyword. You can use the lambda keyword to create small
anonymous functions. For more details visit Python
Training Institutes in Pune.
Lambda
forms can take any number of arguments but return just one value in the form of
an expression. They cannot contain commands or multiple expressions.
An
anonymous function cannot be a direct call to print because lambda requires an
expression. Lambda
functions have their own local namespace and cannot access variables other than
those in their parameter list and those in the global namespace.
Although it
appears that lambda's are a one-line version of a function, they are not
equivalent to inline statements in C or C++, whose purpose is by passing
function stack allocation during invocation for performance reasons.
Built-In Function in Python:
1) Print()-to
print any value or anything on the screen
2) Abs()-Return
the absolute value of a numeric value
3) Round()-Return
the rounded value of a numeric value
4) Max()-return
the largest item
5) Sorted()-it
will sort in ascending order
6) Len()-give
the number of element in the list or number of character of the string
7) Type()-give
the type of variable
8) Zip()-create
the tuples of variable
9) Chr()-return
the string representing the character whose Unicode point is the integer given
in ()
10) Filter()-Give
an iterator for the element of inerrable for which the function give true
