Bagaimana cara SALIN IMPOR file json ke postgres?

Saya akhirnya menggunakan blog Andre Dunstan dan jawaban SO ini yang mengatakan untuk memformat json dengan cara tertentu menggunakan perintah salin.

Karena struktur saya cukup ditentukan untuk file yang saya parsing, saya berakhir dengan skrip berikut.

def file_len(fname):
    # to find the number of lines in the file.
    # Has been pretty efficient even for millions of records
    with open(fname) as f:
        for i, l in enumerate(f):
            pass
    return i + 1

INPUTFILE = '/path/to/input.json'
OUTPUTFILE = '/path/to/output.json.csv'
LEN = file_len(INPUTFILE)
with open(OUTPUTFILE, 'w') as fo:
    with open(INPUTFILE, 'r') as fi:
        for i, l in enumerate(fi):
            # I skip the first line
            if i == 0: continue 
            
            # To remove the ']}}' from the end
            elif i+1 == LEN: _ = fo.write(l[:-3])
            
            # To remove the ',' from the end 
            # and add \n since write does not add newline on its own
            else: _ = fo.write(l[:-2]+'\n') 

# load statement

import sqlalchemy
POSTGRESQL = f'postgresql+psycopg2://{USERNAME}:{PASSWORD}@{HOSTNAME}/{DB}'
engine = sqlalchemy.create_engine(POSTGRESQL, echo=True)
            
con = engine.connect()
trans = con.begin()
LOAD_SQL = f"COPY tablename from '{OUTPUTFILE}' with csv delimiter E'\x01' quote E'\x02' null as '';"
try:
    con.execute(LOAD_SQL)
    trans.commit()
except Exception as e:
    trans.rollback()
finally:
    con.close()