submissions_2_parquet_part1.py

   1 #!/usr/bin/env python3
   2
   3 # two stages:
   4 # 1. from gz to arrow parquet (this script)
   5 # 2. from arrow parquet to spark parquet (submissions_2_parquet_part2.py)
   6
   7 from datetime import datetime
   8 from multiprocessing import Pool
   9 from itertools import islice
  10 from helper import find_dumps, open_fileset
  11 import pandas as pd
  12 import pyarrow as pa
  13 import pyarrow.parquet as pq
  14 import simdjson
  15 import fire
  16 import os
  17
  18 parser = simdjson.Parser()
  19
  20 def parse_submission(post, names = None):
  21     if names is None:
  22         names = ['id','author','subreddit','title','created_utc','permalink','url','domain','score','ups','downs','over_18','has_media','selftext','retrieved_on','num_comments','gilded','edited','time_edited','subreddit_type','subreddit_id','subreddit_subscribers','name','is_self','stickied','quarantine','error']
  23
  24     try:
  25         post = parser.parse(post)
  26     except (ValueError) as e:
  27         #        print(e)
  28         #        print(post)
  29         row = [None for _ in names]
  30         row[-1] = "Error parsing json|{0}|{1}".format(e,post)
  31         return tuple(row)
  32
  33     row = []
  34
  35     for name in names:
  36         if name == 'created_utc' or name == 'retrieved_on':
  37             val = post.get(name,None)
  38             if val is not None:
  39                 row.append(datetime.fromtimestamp(int(post[name]),tz=None))
  40             else:
  41                 row.append(None)
  42         elif name == 'edited':
  43             val = post[name]
  44             if type(val) == bool:
  45                 row.append(val)
  46                 row.append(None)
  47             else:
  48                 row.append(True)
  49                 row.append(datetime.fromtimestamp(int(val),tz=None))
  50         elif name == "time_edited":
  51             continue
  52         elif name == 'has_media':
  53             row.append(post.get('media',None) is not None)
  54
  55         elif name not in post:
  56             row.append(None)
  57         else:
  58             row.append(post[name])
  59     return tuple(row)
  60
  61 def parse_dump(partition):
  62
  63     N=10000
  64     stream = open_fileset([f"/gscratch/comdata/raw_data/reddit_dumps/submissions/{partition}"])
  65     rows = map(parse_submission,stream)
  66     schema = pa.schema([
  67         pa.field('id', pa.string(),nullable=True),
  68         pa.field('author', pa.string(),nullable=True),
  69         pa.field('subreddit', pa.string(),nullable=True),
  70         pa.field('title', pa.string(),nullable=True),
  71         pa.field('created_utc', pa.timestamp('ms'),nullable=True),
  72         pa.field('permalink', pa.string(),nullable=True),
  73         pa.field('url', pa.string(),nullable=True),
  74         pa.field('domain', pa.string(),nullable=True),
  75         pa.field('score', pa.int64(),nullable=True),
  76         pa.field('ups', pa.int64(),nullable=True),
  77         pa.field('downs', pa.int64(),nullable=True),
  78         pa.field('over_18', pa.bool_(),nullable=True),
  79         pa.field('has_media',pa.bool_(),nullable=True),
  80         pa.field('selftext',pa.string(),nullable=True),
  81         pa.field('retrieved_on', pa.timestamp('ms'),nullable=True),
  82         pa.field('num_comments', pa.int64(),nullable=True),
  83         pa.field('gilded',pa.int64(),nullable=True),
  84         pa.field('edited',pa.bool_(),nullable=True),
  85         pa.field('time_edited',pa.timestamp('ms'),nullable=True),
  86         pa.field('subreddit_type',pa.string(),nullable=True),
  87         pa.field('subreddit_id',pa.string(),nullable=True),
  88         pa.field('subreddit_subscribers',pa.int64(),nullable=True),
  89         pa.field('name',pa.string(),nullable=True),
  90         pa.field('is_self',pa.bool_(),nullable=True),
  91         pa.field('stickied',pa.bool_(),nullable=True),
  92         pa.field('quarantine',pa.bool_(),nullable=True),
  93         pa.field('error',pa.string(),nullable=True)])
  94
  95     if not os.path.exists("/gscratch/comdata/output/temp/reddit_submissions.parquet/"):
  96         os.mkdir("/gscratch/comdata/output/temp/reddit_submissions.parquet/")
  97
  98     with pq.ParquetWriter(f"/gscratch/comdata/output/temp/reddit_submissions.parquet/{partition}",schema=schema,compression='snappy',flavor='spark') as writer:
  99         while True:
 100             chunk = islice(rows,N)
 101             pddf = pd.DataFrame(chunk, columns=schema.names)
 102             table = pa.Table.from_pandas(pddf,schema=schema)
 103             if table.shape[0] == 0:
 104                 break
 105             writer.write_table(table)
 106
 107         writer.close()
 108
 109 def gen_task_list(dumpdir="/gscratch/comdata/raw_data/reddit_dumps/submissions"):
 110     files = list(find_dumps(dumpdir,base_pattern="RS_20*.*"))
 111     with open("parse_submissions_task_list",'w') as of:
 112         for fpath in files:
 113             partition = os.path.split(fpath)[1]
 114             of.write(f'python3 submissions_2_parquet_part1.py parse_dump {partition}\n')
 115
 116 if __name__ == "__main__":
 117     fire.Fire({'parse_dump':parse_dump,
 118               'gen_task_list':gen_task_list})