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. … Read more
If you’re like me, you may have asked yourself the following question: Why is it string.join(list) instead of list.join(string) in Python? ? The join method works with any iterable, not just with lists. Therefore, you’d have to implement it in hundreds of classes instead of just one (in the string class). Additionally, join() works only … Read more
Problem: Given two lists [1, 2, 2, 4] and [2, 5, 5, 5, 6]. How do you combine those lists to the new list [1, 2, 2, 4, 5, 6] by removing the duplicates in the second list? Note: You want to remove all duplicates in the second list and the elements in the second … Read more
To intersect multiple sets, stored in a list l, use the Python one-liner l.pop().intersection(*l) that takes the first set from the list, calls the intersection() method on it, and passes the remaining sets as arguments by unpacking them from the list. A set is a unique collection of unordered elements. The intersection operation creates a … Read more
The most efficient way to join multiple sets (stored in a list of sets), use the Python one-liner set().union(*list) that creates a new set object, calls the union() method on the new object, and unpacks all sets from the list of sets into the union() method’s argument list. A set is a unique collection of … Read more
Do you want to convert a Python set to a list? Use the list(…) constructor and pass the set object as an argument. For example, to convert a set of strings friends into a list, use the code expression list(friends). Here’s an example code snippet that converts the set to a list using the list(…) … Read more
Do you have a list but you want to convert it to a Python set? No problem! Use the set(…) constructor and pass the list object as an argument. For example, if you have a list of strings friends, you can convert it to a set using the call set(friends). Here’s an example code snippet: … Read more