If used without argument, Python’s built-in dir() function returns the function and variable names defined in the local scope—the namespace of your current module. If used with an object argument, dir(object) returns a list of attribute and method names defined in the object’s scope. Thus, dir() returns all names in a given scope. Usage Learn … Read more
Python’s built-in dict() function creates and returns a new dictionary object from the comma-separated argument list of key = value mappings. For example, dict(name = ‘Alice’, age = 22, profession = ‘programmer’) creates a dictionary with three mappings: {‘name’: ‘Alice’, ‘age’: 22, ‘profession’: ‘programmer’}. A dictionary is an unordered and mutable data structure, so it … Read more
Python’s built-in getattr(object, string) function returns the value of the object‘s attribute with name string. If this doesn’t exist, it returns the value provided as an optional third default argument. If that doesn’t exist either, it raises an AttributeError. An example is getattr(porsche, ‘speed’) which is equivalent to porsche.speed. Usage Learn by example! Here’s an … Read more
Python’s built-in setattr(object, string, value) function takes three arguments: an object, a string, and an arbitrary value. It sets the attribute given by the string on the object to the specified value. After calling the function, there’s a new or updated attribute at the given instance, named and valued as provided in the arguments. For … Read more
Python’s built-in delattr() function takes an object and an attribute name as arguments and removes the attribute from the object. The call delattr(object, ‘attribute’) is semantically identical to del object.attribute. This article shows you how to use Python’s built-in delattr() function. Usage Learn by example! Here’s an example on how to use the delattr() built-in … Read more
If you’re like me, you love those TLDR; overviews to grasp the big picture quickly. Here is mine about Python’s compile() function: Python’s built-in compile() method returns an executable code object as an “Abstract Syntax Tree” represented as an ast object. By passing this code object into the exec() or eval() functions, you can run … Read more
This tutorial shows you how to use Python’s built-in eval() function. Why Using It? The main application of eval() is to take user input at runtime and run it as a Python expression. This way, you can create a calculator or allow users to perform custom computations on a computing cluster. However, this use also … Read more
Exponents are superscript numbers that describe how many times you want to multiply a number by itself. Calculating a value raised to the power of another value is a fundamental operation in applied mathematics such as finance, machine learning, statistics, and data science. This tutorial shows you how to do it in Python! Definition For … Read more
Python’s exec() function executes the Python code you pass as a string or executable object argument. This is called dynamic execution because, in contrast to normal static Python code, you can generate code and execute it at runtime. This way, you can run programmatically-created Python code. Have you ever wondered about the limits of a … Read more
The Python complex() method returns a complex number object. You can either pass a string argument to convert the string to a complex number, or you provide the real and imaginary parts to create a new complex number from those. This article shows you how to use Python’s built-in complex() constructor. You’ll not only learn … Read more
Static methods are special cases of class methods. They’re bound to a class rather than an instance, so they’re independent on any instance’s state. Python’s built-in function staticmethod() prefixes a method definition as an annotation @staticmethod. This annotation transforms a normal instance method into a static method. The difference between static (class) methods and instance … Read more
Python’s built-in function classmethod() prefixes a method definition in a class as an annotation @classmethod. This annotation transforms a normal instance method into a class method. The difference between class and instance method is that Python passes the class itself as a first implicit argument of the method rather than the instance on which it … Read more