![Numpy Weighted Average np.average(array, axis=0, weights=[0.1,0.1,0.8])](https://blog.finxter.com/wp-content/uploads/2018/08/Numpy-Weighted-Average.png)
Problem Formulation: How to calculate the weighted average of the elements in a NumPy array? Definition weighted average: Each array element has an associated weight. The weighted average is the sum of all array elements, properly weighted, divided by the sum of all weights. Here’s the problem exemplified: Quick solution: Before we discuss the solution … Read more
Python’s built-in repr(obj) function returns the standard string representation of the provided object. This often includes the type and memory address of the object—for lack of further information. For example, the returned string representation may be ‘<main.Car object at 0x000001F66D11DBE0>’ for a custom object of type Car. The function internally calls the method obj.__repr__() which … Read more
Python’s built-in str(x) function converts the object x to a string using the x.__str__() method or, if non-existent, the repr(x) built-in function to obtain the string conversion. Syntax str() Syntax: str(object) # –> Most common case: convert an object to a string str(object=b”, encoding=’utf-8′, errors=’strict’) # –> Not so common case: Converts a bytes or … Read more
NumPy is a popular Python library for data science focusing on arrays, vectors, and matrices. This article introduces the np.average() function from the NumPy library. When applied to a 1D array, this function returns the average of the array values. When applied to a 2D array, NumPy simply flattens the array. The result is the … Read more
Python’s built-in round() function takes two input arguments: a number and an optional precision in decimal digits. It rounds the number to the given precision and returns the result. The return value has the same type as the input number—or integer if the precision argument is omitted. Per default, the precision is set to 0 … Read more
NumPy is a popular Python library for data science for array, vector, and matrix computations. This puzzle introduces basic indexing of elements in NumPy arrays. Problem Formulation: How to index elements in NumPy arrays? Indexing 1D Arrays with Positive Indices The most simple use of indexing is with the square bracket notation and positive integers: … Read more
Problem Formulation: How to calculate the standard deviation in NumPy? Differentiations: There are many different variants of this problem: Calculate the standard deviation of a 1D array Calculate the standard deviation of a 2D array Calculate the standard deviation of a 3D array Then you can also calculate the standard deviation along an axis: Calculate … Read more
Python’s built-in issubclass(X, Y) function takes a class X and a class Y and returns True if the X is an instance of Y and otherwise False. The argument Y can also be a tuple in which case it checks whether X is a subclass of any class in the tuple—such as in issubclass(X, (class_1, … Read more
Did you check the news today, or receive an email newsletter from a company? Both modes of communication follow the publish-subscribe communication pattern. This article will show you how to implement your own PubSub system in Python using the flexible PyPubSub library. If you already know about the PubSub concept, feel free to move to … Read more
You can modify a text file in Python using one of the following methods:
1. Using The seek() Method.
2. Using The fileinput Module.
3. Using The splitlines() Method.
4. Using the regex module and the
split() and insert() methods.
Python’s built-in reversed(sequence) function returns a reverse iterator over the values of the given sequence such as a list, a tuple, or a string. Usage Learn by example! Here are some examples of how to use the reversed() built-in function. The most basic use is on a Python list: You can see that the return … Read more
Python’s built-in isinstance(object, class) function takes an object and a class as input arguments. It returns True if the object is an instance of the class. Otherwise, it returns False. Instead of a class, you can also pass a tuple of classes to check if the object is an instance of any of the classes … Read more