Lists - Useful Functions/Methods in Python
Some Useful Functions/Methods
It's time to clarify our terminology. There is a distinction between a
function and a
method,
even though both represent
subroutines—sequences of code that perform specific tasks. A method is a
function
that belongs to a class or data type, etc.
For example,
len() is a built-in
function that we can call directly to determine the length of a string, a list, etc.:
len(list)
Methods of the
list type can be found
[
here]
in the official documentation of
Python 3. We will only present some that are particularly important for now.
Associated methods are used as shown below:
list.method_name(parameters)
where
list is the name of the
variable, and
method_name is the name of the
method.
EXAMPLES
We start with
a list that contains some integers. Execute the following program:
Editor - lesson_11_lists.py
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DETAILS
The function
sum(numeric_list, initial) returns the sum of the values of the elements in a list that contains only numeric values; optionally, if
initial is specified, the sum is added to this value.
The functions
min() and
max() return the smallest and, respectively, the largest value held by the elements of the list.
The method
count(element) returns the number of occurrences of the element sent as a parameter in the list.
Limitations of the Online System
This web page contains
a simulation of working in Python, and some
methods may not work online, but they are documented and can be executed on your computer after you [
install the Python environment].
Once you have installed the Python environment on your PC, try:
• The
sort() method sorts the elements of a list in ascending order:
We can also sort a list in
descending order by calling the function as shown below:
• The
reverse() method reverses the elements of the list, whether they are sorted or not:
Enough with the theory. Let's apply what you've learned!