You have to use a different literate for starred ones:
literate=
*{-}{{{\color{ipython_purple}-}}}1,
If you add more literates after this one (without the star) they will behave as if they were starred. For example
literate=
*{-}{{{\color{ipython_purple}-}}}1
{?}{{{\color{ipython_purple}?}}}1,
Also, the quotes at the beginning of the listing are due to the fact that there's a missing comma after
morestring=[s]{u"""}{"""}
MWE:
\documentclass{report}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage[T1]{fontenc}
\usepackage{xcolor}
\definecolor{maroon}{cmyk}{0, 0.87, 0.68, 0.32}
\definecolor{halfgray}{gray}{0.55}
\definecolor{ipython_frame}{RGB}{207, 207, 207}
\definecolor{ipython_bg}{RGB}{247, 247, 247}
\definecolor{ipython_red}{RGB}{186, 33, 33}
\definecolor{ipython_green}{RGB}{0, 128, 0}
\definecolor{ipython_cyan}{RGB}{64, 128, 128}
\definecolor{ipython_purple}{RGB}{170, 34, 255}
\usepackage{listings}
\lstset{
breaklines=true,
%
extendedchars=true,
literate=
{á}{{\'a}}1 {é}{{\'e}}1 {í}{{\'i}}1 {ó}{{\'o}}1 {ú}{{\'u}}1
{Á}{{\'A}}1 {É}{{\'E}}1 {Í}{{\'I}}1 {Ó}{{\'O}}1 {Ú}{{\'U}}1
{à}{{\`a}}1 {è}{{\`e}}1 {ì}{{\`i}}1 {ò}{{\`o}}1 {ù}{{\`u}}1
{À}{{\`A}}1 {È}{{\'E}}1 {Ì}{{\`I}}1 {Ò}{{\`O}}1 {Ù}{{\`U}}1
{ä}{{\"a}}1 {ë}{{\"e}}1 {ï}{{\"i}}1 {ö}{{\"o}}1 {ü}{{\"u}}1
{Ä}{{\"A}}1 {Ë}{{\"E}}1 {Ï}{{\"I}}1 {Ö}{{\"O}}1 {Ü}{{\"U}}1
{â}{{\^a}}1 {ê}{{\^e}}1 {î}{{\^i}}1 {ô}{{\^o}}1 {û}{{\^u}}1
{Â}{{\^A}}1 {Ê}{{\^E}}1 {Î}{{\^I}}1 {Ô}{{\^O}}1 {Û}{{\^U}}1
{œ}{{\oe}}1 {Œ}{{\OE}}1 {æ}{{\ae}}1 {Æ}{{\AE}}1 {ß}{{\ss}}1
{ç}{{\c c}}1 {Ç}{{\c C}}1 {ø}{{\o}}1 {å}{{\r a}}1 {Å}{{\r A}}1
{€}{{\EUR}}1 {£}{{\pounds}}1
}
%%
%% Python definition (c) 1998 Michael Weber
%% Additional definitions (2013) Alexis Dimitriadis
%% modified by me (should not have empty lines)
%%
\lstdefinelanguage{iPython}{
morekeywords={access,and,break,class,continue,def,del,elif,else,except,exec,finally,for,from,global,if,import,in,is,lambda,not,or,pass,print,raise,return,try,while},%
%
% Built-ins
morekeywords=[2]{abs,all,any,basestring,bin,bool,bytearray,callable,chr,classmethod,cmp,compile,complex,delattr,dict,dir,divmod,enumerate,eval,execfile,file,filter,float,format,frozenset,getattr,globals,hasattr,hash,help,hex,id,input,int,isinstance,issubclass,iter,len,list,locals,long,map,max,memoryview,min,next,object,oct,open,ord,pow,property,range,raw_input,reduce,reload,repr,reversed,round,set,setattr,slice,sorted,staticmethod,str,sum,super,tuple,type,unichr,unicode,vars,xrange,zip,apply,buffer,coerce,intern},%
%
sensitive=true,%
morecomment=[l]\#,%
morestring=[b]',%
morestring=[b]",%
%
morestring=[s]{'''}{'''},% used for documentation text (mulitiline strings)
morestring=[s]{"""}{"""},% added by Philipp Matthias Hahn
%
morestring=[s]{r'}{'},% `raw' strings
morestring=[s]{r"}{"},%
morestring=[s]{r'''}{'''},%
morestring=[s]{r"""}{"""},%
morestring=[s]{u'}{'},% unicode strings
morestring=[s]{u"}{"},%
morestring=[s]{u'''}{'''},%
morestring=[s]{u"""}{"""},%
%
% {replace}{replacement}{lenght of replace}
% *{-}{-}{1} will not replace in comments and so on
literate=
{á}{{\'a}}1 {é}{{\'e}}1 {í}{{\'i}}1 {ó}{{\'o}}1 {ú}{{\'u}}1
{Á}{{\'A}}1 {É}{{\'E}}1 {Í}{{\'I}}1 {Ó}{{\'O}}1 {Ú}{{\'U}}1
{à}{{\`a}}1 {è}{{\`e}}1 {ì}{{\`i}}1 {ò}{{\`o}}1 {ù}{{\`u}}1
{À}{{\`A}}1 {È}{{\'E}}1 {Ì}{{\`I}}1 {Ò}{{\`O}}1 {Ù}{{\`U}}1
{ä}{{\"a}}1 {ë}{{\"e}}1 {ï}{{\"i}}1 {ö}{{\"o}}1 {ü}{{\"u}}1
{Ä}{{\"A}}1 {Ë}{{\"E}}1 {Ï}{{\"I}}1 {Ö}{{\"O}}1 {Ü}{{\"U}}1
{â}{{\^a}}1 {ê}{{\^e}}1 {î}{{\^i}}1 {ô}{{\^o}}1 {û}{{\^u}}1
{Â}{{\^A}}1 {Ê}{{\^E}}1 {Î}{{\^I}}1 {Ô}{{\^O}}1 {Û}{{\^U}}1
{œ}{{\oe}}1 {Œ}{{\OE}}1 {æ}{{\ae}}1 {Æ}{{\AE}}1 {ß}{{\ss}}1
{ç}{{\c c}}1 {Ç}{{\c C}}1 {ø}{{\o}}1 {å}{{\r a}}1 {Å}{{\r A}}1
{€}{{\EUR}}1 {£}{{\pounds}}1
%
{^}{{{\color{ipython_purple}\^{}}}}1
{=}{{{\color{ipython_purple}=}}}1
%
{+}{{{\color{ipython_purple}+}}}1
{*}{{{\color{ipython_purple}$^\ast$}}}1
{/}{{{\color{ipython_purple}/}}}1
%
{+=}{{{+=}}}1
{-=}{{{-=}}}1
{*=}{{{$^\ast$=}}}1
{/=}{{{/=}}}1,
literate=
*{-}{{{\color{ipython_purple}-}}}1
{?}{{{\color{ipython_purple}?}}}1,
%
identifierstyle=\color{black}\ttfamily,
commentstyle=\color{ipython_cyan}\ttfamily,
stringstyle=\color{ipython_red}\ttfamily,
keepspaces=true,
showspaces=false,
showstringspaces=false,
%
rulecolor=\color{ipython_frame},
frame=single,
frameround={t}{t}{t}{t},
framexleftmargin=6mm,
numbers=left,
numberstyle=\tiny\color{halfgray},
%
%
backgroundcolor=\color{ipython_bg},
% extendedchars=true,
basicstyle=\scriptsize,
keywordstyle=\color{ipython_green}\ttfamily,
}
\begin{document}
\begin{lstlisting}[language=iPython]
<- #there shouldn't be quotation marks
"""
---------
sin2_theta = np.sin(theta)**2 - a + b ?
"""
import math
import numpy as np
from lib.analytical import csa
MAS = math.degrees(math.acos(math.sqrt(1/3)))/360 * 2* math.pi + a -b ?
\end{lstlisting}
\end{document}
Output
Note that I've added two ? in your listing just to show the effect, remove them as well as {?}{{{\color{ipython_purple}?}}}1 in the second literate.
Best Answer
When typesetting C code in non-monospaced fonts, I've certainly found the "literate programming" options useful.
What I've used them for is specifying typography for symbol pairs that aren't very readable in the standard non-monospaced font -- not replacing them with a different symbol, but adjusting to make the same symbols more readable. For instance, "--" doesn't look right in Times, so I've used
literate={--}{{\texttt{--}}to make that look better.Meanwhile, when one's using illustrative pseudocode in discussions of algorithms that are detached from details of programming language syntax, I do think it's useful to use non-programming symbols. For one thing, it helps make it clear that what you are writing is not compilable C code -- even if it has a C-like syntax, and is really just C with irrelevant bits removed. (Or Lisp, or whatever.) And, since the "irrelevant bits" are going to vary from discussion to discussion, I haven't found that one specific pseudocode format applies to everything.