parseConfig/parseConfig.py

import json
import re
import sys
import os

#first pass
def convert(fo,setup=None):
   #take RHS values that will be used later on and replace common patterns with replacePattern

   #patterns are defined in replacePattern

    
   if not isinstance(fo,dict):
       return fo

   if 'setVariables' in fo:
      for v in fo['setVariables']:
         fo[v]=replacePattern(fo[v],setup)

   #descend
   for c in fo:
      if c=='setVariables':
         continue
      if isinstance(fo[c],dict):
         fo[c]=convert(fo[c])
         continue
      if isinstance(fo[c],list):
         fo[c]=[convert(x) for x in fo[c]]
         continue
   return fo

def replacePattern(v,setup=None):

   print('Replacing v={}'.format(v))

   #local HOME variable of the user executing the code
   if v.find('__home__')>-1: 
      x=re.sub(r'__home__',os.path.expanduser('~'),v)
      print('Matching home {}->{}'.format(v,x))
      return x
   if v.find('__[env]home__')>-1:
      x=re.sub(r'__\[env\]home__',os.path.expanduser('~'),v)
      print('Matching home {}->{}'.format(v,x))
      return x
      
   
   #backward compatibility where no setup is used
   if not setup:
      return v

   #__[setup:X]Y__ will be replaced by setup[X][Y], where X is commonly a path
   pattern=r'__\[setup:([^\]]*)\](.*)(?=__)__'
   m=re.findall(pattern,v)
   print(m)
   if len(m)==1:
      g=m[0]
      return re.sub(pattern,setup[g[0]][g[1]],v)
   return v




def convertValues(pars):
    replacements={v:pars[v] for v in pars['setVariables']}
    return convertValuesR(pars,replacements)

def convertValuesR(pars,replacements):

    #dict
    if isinstance(pars,dict):
        for c in pars:
            if c=='setVariables':
                continue
            if c in replacements:
                continue
            if isinstance(pars[c],dict):
                pars[c]=convertValuesR(pars[c],replacements)
                continue
            if isinstance(pars[c],list):
                pars[c]=[convertValuesR(x,replacements) for x in pars[c]]
                continue
            for r in replacements:
               try:
                  pars[c]=re.sub(r,replacements[r],pars[c])
               except TypeError:
                  #direct values (int, etc.) don't work with regexp, but they don't need replacements anyhow
                  pass
        return pars

    #list
    if isinstance(pars,list):
        return [convertValuesR(x,replacements) for x in pars]

    #value/leaf
    for r in replacements:
        pars=re.sub(r,replacements[r],pars)
    return pars