why does my code return a value of zero $.$

Python code :

import numpy as np

# Given reaction mechanism $($coefficients are already corrected$)$

finput$=[$

$"$C$3$H$8<->$ CH$3*+$ C$2$H$5*",$

$"$C$3$H$8+$ H$*<->$ H$2+$ C$3$H$7*",$

$"$C$3$H$7*<->$ C$3$H$6+$ H$*",$

$"$C$2$H$5*<->$ C$2$H$4+$ H$*",$

$"$C$3$H$7*<->$ C$2$H$4+$ CH$3*",$

$"$C$2$H$5*+$ C$3$H$8<->$ C$2$H$6+$ C$3$H$7*",$

$"$CH$3*+$ C$3$H$8<->$ CH$4+$ C$3$H$7*",$

$"$CH$3*+$ C$3$H$7*<->$ C$3$H$6+$ CH$4"$

$]$

reactions $=$ list$()$

for line in finput:

stripped$\_$line $=$ line.strip$()$

if stripped$\_$line$[0]==\text{'}$#$\text{'}$:

continue

if stripped$\_$line$[$:$2]==\text{'}..\text{'}$:

continue

for r in reactions:

i $=$ reactions.index$($r$)$

species$\_$tmp $=$ list$()$ # temporary list for species

for r in reactions:

left $=$ r$.$split$(\text{'}<=>\text{'})[0].$strip$()$ # reactants side

right $=$ r$.$split$(\text{'}<=>\text{'})[1].$strip$()$ # products side

left$\_$terms $=$ left.split$(\text{'}+\text{'})$ # reactant species w$/$ stoichiometric coeff.

right$\_$terms $=$ right.split$(\text{'}+\text{'})$ # product species w$/$ stoichiometric coeff.

terms $=[$t$.$strip$()$ for t in left$\_$terms$]+[$t$.$strip$()$ for t in right$\_$terms$]$ # concatenate list comprehensions

for i in terms:

tmp $=$ i$.$split$(\text{'}\text{'})$ # split stoichiometric coefficient from species name

assert len$($tmp$)==1$ or len$($tmp$)==2,\text{'}$ terms $=\%$r$,$ i $=\%$r$,$ tmp $=\%$r $\text{'}\%($terms$,$ i$,$ tmp$)$

if len$($tmp$)==$ f$=2$:

species$\_$tmp$.$append$($tmp$[1].$strip$())$ # species name if there is a stoichiometric coeff.

else:

species$\_$tmp$.$append$($i$.$strip$())$ # species name if there is no stoichiometric coeff.

species$\_$filtered $=$ set$($species$\_$tmp$)$ # filter species as a set

species $=$ list$($species$\_$filtered$)$ # convert species set to list

print$(\text{'}$

species $=$

$\text{'},$species$)$

print$(\text{'}$# of species $=\text{'},$len$($species$))$