python - Best way to avoid copy-paste and hardcoding -

' hello, community.

problem: have many regex patterns, such as

r'to.*school', r'built.*in' 

and etc. in every case, should execute code, varies situation situation.

example: if pattern 'to.*school', want find verb before 'to' , that's why write like:

for num, part in enumerate(sentence):     if part == 'to':         result = sentence[num-1] 

if pattern 'built.*in', want find time , that's why write like:

for num, part in enumerate(sentence):     if part == 'in':         result = sentence[num+1] 

so there's problem - how can avoid copy-pasting code, if there's on 500 patterns , each pattern has own way result?

my thoughts: understand should kind of database, stores patterns , solutions, how execute solution, if it's string? i'm totally lost.

if there sufficient regularity in code need write function accepts sentence , other things determine it. called parametrisation. example above, presumably simplified examples, you'd have

def process(sentence, parttest, offset):     num, part in enumerate(sentence):         if part == parttest:             return sentence[num+offset] 

and calls first , second examples respectively

result = process( sentence, 'to', -1) result2 = process( sentence, 'in', +1) 

now can obtain parameters (parttest, offset) database. judging post there may regular expression in string form retrieved database well, , process extended include regular expression string compiled on demand.

optimize later: keep local cache of compiled regular expressions in dict, or pickle them, because repeatedly compiling same 1 may nontrivial waste of cpu.

hope helps.