Python Operators

[bhishan]

https://www.thetaranights.com/python-operators/

[trombonechamp]

The section on assignment operators is incorrect. x += y modifies the object x, whereas x = x + y doesn't. For example,

  >> a = [1, 2, 3]
  >> b = a
  >> a += [4]
  >> a
  [1, 2, 3, 4]
  >> b
  [1, 2, 3, 4]

By comparison,

  >> a = [1, 2, 3]
  >> b = a
  >> a = a + [4]
  >> a
  [1, 2, 3, 4]
  >> b
  [1, 2, 3]

[bhishan → trombonechamp]

This is especially true for the case of mutables. I agree it should've been mentioned on the blog. Do you mind if I add this thread to the comments section of the blog.

[haney]

After you're mastered all the available operators the real fun begins when you start writing your own operator methods on classes http://thepythonguru.com/python-operator-overloading/

The ability to override operators is one of the things I miss most from Python when I'm forced to write javascript.

[bhishan → haney]

That's a great post. Thanks for the link. These methods do enhance classes to the best. I also made a short blog about magic methods. Could be relevant to someone reading the threads https://www.thetaranights.com/magic-methods-in-python/

[swpdkfn → haney]

There could also be mention of the "right" variants e.g. __rmul__ vs. __mul__. https://stackoverflow.com/questions/5181320/under-what-circu... gives a rough sketch of what they're about.

[bhishan → swpdkfn]

This is indeed a very helpful read. Thanks for the link.

[A2017U1]

There's a few missing:

@ For matrix multiplication, equivalent to __matmul__

@= <<= >>= ^= |= Assignment operators

[bhishan → A2017U1]

Thanks for the mentions. I am sure it is helpful to anyone reading the threads.

[kalenx]

The := is missing! No wonder Guido would leave its BDFL position!

[bhishan → kalenx]

Isn't that for 3.8 version. I have also made a different blog around PEP 572 some time ago. I will leave the link here so it is helpful for anyone wondering about :=

https://www.thetaranights.com/python-assignment-expression-p...

[mabynogy]

Simple and clear. Even if I don't do Python I learned some good ideas (like the // floor operator).

[bhishan → mabynogy]

I am glad it was helpful.