I have to create python parser (3.6) using code provided by client (2.7), that they used in their company, and it is full of crap like:

if a==1:
if not b:
c = [1,2,3]
if a==2:
if not b:
c = [1,2,3]
if b:
c = [1,2,4]

Or:

text = ""
for i in something:
text += "real text " + some_string + " \n"
text += "another line " + some_string + " \n"
text += "and another " + some_string + " \n"
text += "and so on " + some_string + " \n"
... (many lines instead of one appended text block)

Of course above variable names are just for shortening code, but there are variables like oo, ooo, var_ or var__... cause you know, PEP8 does not exist.

Calling a routine from an instance method (don't even ask, in ABAP, you can do that)