Why is exponentiation applied right to left? Question: I am reading an Intro to Python textbook and came across this line: Operators on the same row have equal precedence and are applied left to right, except for exponentiation, which is applied right to left. I understand most of this, but I do not understand why …
How do "and" and "or" act with non-boolean values? Question: I’m trying to learn python and came across some code that is nice and short but doesn’t totally make sense the context was: def fn(*args): return len(args) and max(args)-min(args) I get what it’s doing, but why does python do this – ie return the value …
Operator @ in python? what does? Question: I have been programming for years in python but now i was reading a program to do linnear regression and i found this. if X.ndim == 1: X = X[:, None] d = X – self.mean precision = np.linalg.inv(self.var) return ( np.exp(-0.5 * np.sum(d @ precision * d, …
What is `1..__truediv__` ? Does Python have a .. ("dot dot") notation syntax? Question: I recently came across a syntax I never seen before when I learned python nor in most tutorials, the .. notation, it looks something like this: f = 1..__truediv__ # or 1..__div__ for python 2 print(f(8)) # prints 0.125 I figured …
What is the difference between i = i + 1 and i += 1 in a 'for' loop? Question: I found out a curious thing today and was wondering if somebody could shed some light into what the difference is here? import numpy as np A = np.arange(12).reshape(4,3) for a in A: a = a …
Is there a difference between != and <> operators in Python? Question: I tried searching, but could not find much about the <> operator. Python – Basic Operators mentions that <> is "similar" to the != operator and does not say what is different or how it is different. My tests seem to show it …
Overriding the 'not' operator in Python Question: I cannot find the method corresponding to not x operator. There is one for and, or, and xor, though. Where is it? 3. Data model Asked By: ArekBulski || Source Answers: There is one for and, or, and xor, though The methods you’re looking at are for bitwise …
^=, -= and += symbols in Python Question: I am quite experienced with Python, but recently, when I was looking at the solutions for the codility sample tests I encountered the operators -=, +=, ^= and I am unable to figure out what they do. Perhaps could anyone explain the context in which they are …
What does ,= mean in python? Question: I wonder what ,= or , = means in python? Example from matplotlib: plot1, = ax01.plot(t,yp1,’b-‘) Asked By: benni || Source Answers: It’s a form of tuple unpacking. With parentheses: (plot1,) = ax01.plot(t,yp1,’b-‘) ax01.plot() returns a tuple containing one element, and this element is assigned to plot1. Without …
How do I do exponentiation in python? Question: def cube(number): return number^3 print cube(2) I would expect cube(2) = 8, but instead I’m getting cube(2) = 1 What am I doing wrong? Asked By: Rohan Sobha || Source Answers: ^ is the xor operator. ** is exponentiation. 2**3 = 8 Answered By: Stefan Kendall You …
