It shows up fairly frequently in pseudocode, especially for BNF syntax rules. I also (probably as a result) have come across it often-ish in embedded DSLs if th

It shows up fairly frequently in pseudocode, especially for BNF syntax rules. I also (probably as a result) have come across it often-ish in embedded DSLs if the host language already uses = for assignment. So from the perspective of Python as executable pseudocode it makes some sense.