A set is an unordered collection of elements. Each element can exist at most once in a set. There are no duplicate elements. Goal: How to intersect to Python sets? Solution: set_a & set_b The set intersection operator set_a & set_b intersects two sets, i.e., creates a new set with elements that exist in both …
To remove duplicates from a Python list while preserving the order of the elements, use the code list(dict.fromkeys(list)) that goes through two phases: (1) Convert the list to a dict using the dict.fromkeys() function with the list elements as keys and None as dict values. (2) Convert the dictionary back to a list using the …
How to Remove Duplicates From a Python List While Preserving Order? Read More »
This is a running document in which I’ll answer all questions regarding the single line of Python code. It’s based on my interactive collection here but without the slow videos and embedded code shells. Let’s get started! Python One Line If Else You can use a simple if statement in a single line of code. …
It’s quite common for your code to throw a typeerror, especially if you’re just starting out with Python. The reason for this is that the interpreter expects variables of certain types in certain places in the code. We’ll look at a specific example of such an error: “typeerror: ‘int’ object is not iterable”. Exercise: Run …
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Summary: To split a string and keep the delimiters/separators you can use one of the following methods: Use a regex module and the split() method along with \W special character. Use a regex module and the split() method along with a negative character set [^a-zA-Z0-9]. Use a regex module and the split() method along with …
Do you want to one-linerize the append() method in Python? I feel you—writing short and concise one-liners can be an addiction! 🙂 This article will teach you all the ways to append one or more elements to a list in a single line of Python code! Python List Append Let’s quickly recap the append method …
Do you want to learn Python but you’re overwhelmed and you don’t know where to start? Learn with Python cheat sheets! They compress the most important information in an easy-to-digest 1-page format. Here’s the new Python cheat sheet I just created—my goal was to make it the world’s most concise Python cheat sheet!
This is a running document in which I’ll answer all questions regarding the single line of Python code. If you want to become a one-liner wizard, check out my book “Python One-Liners”! 🙂 This document contains many interactive code shells and videos to help you with your understanding. However, it’s pretty slow because of all …
Problem: Given are two lists l1 and l2. You want to perform either of the following: 1. Boolean Comparison: Compare the lists element-wise and return True if your comparison metric returns True for all pairs of elements, and otherwise False. 2. Difference: Find the difference of elements in the first list but not in the …
The Most Pythonic Way to Compare Two Lists in Python Read More »
Short answer: The most Pythonic way to compute the difference between two lists l1 and l2 is the list comprehension statement [x for x in l1 if x not in set(l2)]. This works even if you have duplicate list entries, it maintains the original list ordering, and it’s efficient due to the constant runtime complexity …
To check if two unordered lists x and y are identical, compare the converted sets with set(x) == set(y). However, this loses all information about duplicated elements. To consider duplicates, compare the sorted lists with sorted(x) == sorted(y). Due to the efficient merge-sort-like implementation of the sorted() function, this is quite fast for almost-sorted lists. …
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The standard way of checking if an element exists in a list is to use the in keyword. For example, ‘Alice’ in [1, ‘Alice’, 3] will return True while the same returns False for ‘Bob’. If you need to check more complicated conditions, use the any(condition(x) for x in list) function with a generator expression. …
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