Python’s built-in float(value) function converts the argument value to a float number. For example, float(’42’) converts the string value ’42’ into the float number 42.0. Argument value A Python object to be converted into a float number. The value object must have an __float__() method that returns the associated float number—otherwise a ValueError will be … Read more
Python’s built-in int(value) function converts the argument value to an integer number. For example, int(’42’) converts the string value ’42’ into the integer number 42. The int() function on a float argument rounds down to the closest integer. Argument value A Python object to be converted into an integer number. The value object must have … Read more
Python’s built-in filter() function is used to filter out elements that pass a filtering condition. It takes two arguments: function and iterable. The function assigns a Boolean value to each element in the iterable to check whether the element will pass the filter or not. It returns an iterator with the elements that pass the … Read more
Problem Formulation: How to fix the TypeError: len() of unsized object? TypeError: len() of unsized object There are many possible ways why this array may occur. One common pitfall is to use the len() function on a NumPy array with only one value. Example: Let’s consider the minimal example that creates this error message! Reason … Read more
Python’s built-in function len() returns the length of the given string, array, list, tuple, dictionary, or any other iterable. The type of the return value is an integer that represents the number of elements in this iterable. Usage Learn by example! Here are some examples on how to use the len() built-in function. The examples … Read more
Summing up numbers is one of those repetitive tasks you need to do over and over again in your practical code projects. To help you accomplish this task in a concise, readable, and efficient way, Python’s creators have added the built-in sum() function. It sums over all elements in a Python list—or any other iterable … Read more
What is the exec() Function exec() is a built-in Python function that is most commonly used to dynamically execute code, either as a string or object code. To properly understand how we can use exec() to import libraries and modules we need to familiarize ourselves with the syntax of the function itself, as it becomes relevant later: … Read more
Many coders struggle with understanding the zip function. Let’s fix this! The zip() function takes an arbitrary number of iterables and aggregates them to a single iterable, a zip object. It combines the i-th values of each iterable argument into a tuple. Hence, if you pass two iterables, each tuple will contain two values. If … Read more
The Python ord() function takes a character (=string of length one) as an input and returns the Unicode number of this character. For example, ord(‘a’) returns the Unicode number 97. The inverse function of ord() is the chr() function, so chr(ord(‘a’)) returns the original character ‘a’. Here are three examples of passed Unicode characters transformed … Read more
The min() function returns the minimum of the provided arguments. As arguments, you can either pass a number of comma-separated values, or a single iterable. An optional key function argument allows you to customize the calculation of the minimum by explicitly defining the weight of each value in the iterable that is used as a … Read more
The max() function returns the maximum of the provided arguments. You can pass either an arbitrary number of values, comma-separated, or an iterable as arguments. An optional key function argument allows you to customize the calculation of the maximum by explicitly defining the weight of each value in the iterable that is used as a … Read more
Problem: What is the best way to check whether a given object is of a given type? For example, if you have a variable object, how to check if it’s a string? Check with Subclasses Solution: To check if an object is an instance of str or any of its subclasses, use isinstance: Note that … Read more