jsonload_from_script

## For extracting a [JSON] variable by name from JavaScript string or bs4 script-tag ##
## simpler [and more limited] version of findObj_inJS @ https://pastebin.com/UVcLniSG #
## example at https://pastebin.com/5AjaUne0 [other examples at bottom] ################

# from bs4 import BeautifulSoup
import json

## [ inputs explained after definition ]
def jsonload_from_script(inpX, varName, selector='script', prepFn=lambda x:x):
    try: sList = [inpX] if inpX.name=='script' else inpX.select(selector)
    except: sList = inpX if isinstance(inpX, list) else [inpX]
    for s in sList:
        s = getattr(s, 'string', s)
        if not (isinstance(s,str) and s.strip()): continue
        sections = prepFn(s.strip()).split(';')

        for i, section in enumerate(sections):
            name, val = ['', *section.split('=', 1)][-2:]
            if '=' in section and name.strip()==varName:
                sections,t1 = [val]+sections[i+1:],True
                try: return json.loads(val)
                except: break
        else: continue

        while len(sections) > 1:
            try: return json.loads(';'.join(sections))
            except: sections = sections[:-1]
    ### end ###

### INPUTS
#-> inpX: must be a bs4 document/tag/ResultSet or a string or a list of strings
#### [ target variable must be JSON and seaparated from other variables by ; ]
#-> varName: name of the target variable
#### [ only the first variable found with the specified name will be returned ]
#-> selector: a CSS selector bor searching the bs4 document/tag for target script
#### [ if inpX if a script-tag/ResultSet/string/list then selector doesn't matter ]
#-> prepFn: should be a univariate function that takes a string and returns a string
#### [ for modifying the script string before searching for and parsing variable ]

### EXAMPLES:
##### jsonload_from_script(BeautifulSoup('<script>y=8</script>'), 'y') #--> 8
##### jsonload_from_script(['y=8','x=7'], 'x') #--> 7
##### jsonload_from_script('y=8;x=7', 'x') #--> 7
##### jsonload_from_script('y=8;x={"a":1};w="lorem";', 'x') #--> {'a':1}
##### jsonload_from_script('y=8;x={"a":1};w="lorem";', 'w') #--> 'lorem'