Year: 2021

This article will outline several methods which can be used to check that a file exists/is readable in the Python programming language. You may wish to check whether a file exists before reading or writing to it to reduce the number of alerts you need to display to the user or to make sure you aren’t accidentally overwriting an existing file (or a combination of both, letting the user know a file already exists and giving them a choice to overwrite it). Using pathlib to Check if … Read more

This article explores several ways to remove duplicate items from lists in the Python programming language. Using The dict.fromkeys() Method To Remove Duplicates From a List in Python This is the fastest way to remove duplicates from a list in Python. However, the order of the items in the list is not preserved. The fromkeys() method creates a dictionary (a collection of key:value pairs) with keys from a supplied sequence of elements (in this case, a list). As a dictionary cannot contain duplicate keys, they are removed. … Read more

This article will detail how to use the ‘accumulate()’ function in Python and provide some easy-to-follow example code. The accumulate() function in Python will process an iterable (iterables are things like lists, dictionaries, sets, or tuples – collections containing items which can be looped over) – returning the accumulated sum of the value of each item or running a given function on each item. The value of the accumulated value is stored for each step and returned with the result. The syntax and code in this article are written for … Read more

This article will cover the syntax and usage of the filter function. It will work for both Python 2 and Python 3. The filter function in Python takes an iterable (iterables are things like lists, dictionaries, sets, or tuples – collections containing items that can be looped over) and checks that each item matches a set of criteria, removing those that don’t match. It’s a fast and easy way to filter the values in a list or array. Syntax for Python filter() The filter() function does not need to be imported to … Read more

This article will explain the map() function in Python and show you how to use it. The Python map() function applies a given function for all items in an iterable (iterables are things like lists, dictionaries, sets, or tuples – collections containing items that can be looped over). The syntax and code in this article will work for both Python 2 and Python 3. Syntax for Python map() The map() function is built into Python, so nothing needs to be imported. Here’s the syntax: map(FUNCTION, ITERABLE) Note that: FUNCTION is a standard … Read more

This article will show you how to use the Python reduce() function to aggregate data from values in an iterable (iterables are things like lists, dictionaries, sets, or tuples – collections containing items that can be looped over) and reduce them to a single accumulated value. The code and examples in this tutorial will work in Python 3. Syntax for Python reduce() functools.reduce(FUNCTION, ITERABLE[, INITIALIZER]) Note that: FUNCTION is a standard Python function, previously defined in your code It should accept two parameters The first parameter is the current accumulated value up until this point … Read more