ChrisPython’s built-in bin(integer) function takes one integer argument and returns a binary string with prefix “0b”. If you call bin(x) on a non-integer x, it must define the __index__() method that returns an integer associated to x. Otherwise, it’ll throw a TypeError: object cannot be interpreted as an integer. Argument integer An integer value or … Read more
If you’re like me, you’ll regularly sit in front of your code and wonder: how to escape a given character? Challenge: Some characters have a special meaning in Python strings and regular expressions. Say you want to to search for string “(s)” but the regex engine takes the three characters (s) as a matching group. … Read more
Python’s built-in ascii(object) function takes one object argument and returns the string representation of that object. The function calls the repr() built-in function and replaces non-ASCII characters with the character code \x. For example, calling ascii(‘München’) results in the ascii string ‘M\xfcnchen’ by replacing character ü with character code \xfc. Argument object Iterable such as … Read more
This chapter draft is part of my upcoming book “The Art of Clean Code” (NoStarch 2022). You’ll learn about the concept of premature optimization and why it hurts your programming productivity. Premature optimization is one of the main problems of poorly written code. But what is it anyway? Definition Premature Optimization Definition: Premature optimization is … Read more
Python’s built-in any(x) function takes one iterable as an argument x such as a list, tuple, or dictionary. It returns True if at least one of the elements in the iterable evaluates to True using implicit Boolean conversion, otherwise it returns False. If the iterable is empty, e.g., any([]), it returns False because the condition … Read more
You can create an iterable of all pattern matches in a text by using the re.finditer(pattern, text) method: Specification: re.finditer(pattern, text, flags=0) Definition: returns an iterator that goes over all non-overlapping matches of the pattern in the text. The flags argument allows you to customize some advanced properties of the regex engine such as whether … Read more
Problem: You’ve just learned about the list.clear() method in Python. You wonder, what’s its purpose? Why not creating a new list and overwriting the variable instead of clearing an existing list? Example: Say, you have the following list. If you clear the list, it becomes empty: However, you could have accomplished the same thing by … Read more
Python’s built-in all(x) function takes one iterable as an argument x such as a list, tuple, or dictionary. It returns True if all iterable elements evaluate to True using implicit Boolean conversion, otherwise it returns False. If the iterable is empty, all() returns True because the condition is satisfied for all elements. Argument x -> … Read more
Python’s built-in abs(x) function returns the absolute value of the argument x that can be an integer, float, or object implementing the __abs__() function. For a complex number, the function returns its magnitude. The absolute value of any numerical input argument -x or +x is the corresponding positive value +x. Argument x int, float, complex, … Read more
To count a regex pattern multiple times in a given string, use the method len(re.findall(pattern, string)) that returns the number of matching substrings or len([*re.finditer(pattern, text)]) that unpacks all matching substrings into a list and returns the length of it as well. A few hours ago, I wrote a regular expression in Python that matched … Read more
Python comes with many built-in functions you can use without importing a library. The following table goes over all built-in functions in alphabetical order. If you click on any of the provided links, you’ll find an in-depth article with a short explainer video on the Finxter blog to help you improve your skills. Just follow … Read more