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 collections import defaultdict
   8 from os import path
   9 import glob
  10 import json
  11 import re
  12 from datetime import datetime
  13 from subprocess import Popen, PIPE
  14 from multiprocessing import Pool, SimpleQueue
  15
  16 dumpdir = "/gscratch/comdata/raw_data/reddit_dumps/submissions"
  17
  18 def find_json_files(dumpdir):
  19     base_pattern = "RS_20*.*"
  20
  21     files = glob.glob(path.join(dumpdir,base_pattern))
  22
  23     # build a dictionary of possible extensions for each dump
  24     dumpext = defaultdict(list)
  25     for fpath in files:
  26         fname, ext = path.splitext(fpath)
  27         dumpext[fname].append(ext)
  28
  29     ext_priority = ['.zst','.xz','.bz2']
  30
  31     for base, exts in dumpext.items():
  32         found = False
  33         if len(exts) == 1:
  34             yield base + exts[0]
  35             found = True
  36         else:
  37             for ext in ext_priority:
  38                 if ext in exts:
  39                     yield base + ext
  40                     found = True
  41         assert(found == True)
  42
  43 files = list(find_json_files(dumpdir))
  44
  45 def read_file(fh):
  46     lines = open_input_file(fh)
  47     for line in lines:
  48         yield line
  49
  50 def open_fileset(files):
  51     for fh in files:
  52         print(fh)
  53         lines = open_input_file(fh)
  54         for line in lines:
  55             yield line
  56
  57 def open_input_file(input_filename):
  58     if re.match(r'.*\.7z$', input_filename):
  59         cmd = ["7za", "x", "-so", input_filename, '*']
  60     elif re.match(r'.*\.gz$', input_filename):
  61         cmd = ["zcat", input_filename]
  62     elif re.match(r'.*\.bz2$', input_filename):
  63         cmd = ["bzcat", "-dk", input_filename]
  64     elif re.match(r'.*\.bz', input_filename):
  65         cmd = ["bzcat", "-dk", input_filename]
  66     elif re.match(r'.*\.xz', input_filename):
  67         cmd = ["xzcat",'-dk', '-T 20',input_filename]
  68     elif re.match(r'.*\.zst',input_filename):
  69         cmd = ['zstd','-dck', input_filename]
  70     try:
  71         input_file = Popen(cmd, stdout=PIPE).stdout
  72     except NameError as e:
  73         print(e)
  74         input_file = open(input_filename, 'r')
  75     return input_file
  76
  77
  78 def parse_submission(post, names = None):
  79     if names is None:
  80         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','is_submitter','quarantine','error']
  81
  82     try:
  83         post = json.loads(post)
  84     except (json.decoder.JSONDecodeError, UnicodeDecodeError) as e:
  85         #        print(e)
  86         #        print(post)
  87         row = [None for _ in names]
  88         row[-1] = "json.decoder.JSONDecodeError|{0}|{1}".format(e,post)
  89         return tuple(row)
  90
  91     row = []
  92
  93     for name in names:
  94         if name == 'created_utc' or name == 'retrieved_on':
  95             val = post.get(name,None)
  96             if val is not None:
  97                 row.append(datetime.fromtimestamp(int(post[name]),tz=None))
  98             else:
  99                 row.append(None)
 100         elif name == 'edited':
 101             val = post[name]
 102             if type(val) == bool:
 103                 row.append(val)
 104                 row.append(None)
 105             else:
 106                 row.append(True)
 107                 row.append(datetime.fromtimestamp(int(val),tz=None))
 108         elif name == "time_edited":
 109             continue
 110         elif name == 'has_media':
 111             row.append(post.get('media',None) is not None)
 112
 113         elif name not in post:
 114             row.append(None)
 115         else:
 116             row.append(post[name])
 117     return tuple(row)
 118
 119 pool = Pool(28)
 120
 121 stream = open_fileset(files)
 122
 123 N = 100000
 124
 125 rows = pool.imap_unordered(parse_submission, stream, chunksize=int(N/28))
 126
 127 from itertools import islice
 128 import pandas as pd
 129 import pyarrow as pa
 130 import pyarrow.parquet as pq
 131
 132 schema = pa.schema([
 133     pa.field('id', pa.string(),nullable=True),
 134     pa.field('author', pa.string(),nullable=True),
 135     pa.field('subreddit', pa.string(),nullable=True),
 136     pa.field('title', pa.string(),nullable=True),
 137     pa.field('created_utc', pa.timestamp('ms'),nullable=True),
 138     pa.field('permalink', pa.string(),nullable=True),
 139     pa.field('url', pa.string(),nullable=True),
 140     pa.field('domain', pa.string(),nullable=True),
 141     pa.field('score', pa.int64(),nullable=True),
 142     pa.field('ups', pa.int64(),nullable=True),
 143     pa.field('downs', pa.int64(),nullable=True),
 144     pa.field('over_18', pa.bool_(),nullable=True),
 145     pa.field('has_media',pa.bool_(),nullable=True),
 146     pa.field('selftext',pa.string(),nullable=True),
 147     pa.field('retrieved_on', pa.timestamp('ms'),nullable=True),
 148     pa.field('num_comments', pa.int64(),nullable=True),
 149     pa.field('gilded',pa.int64(),nullable=True),
 150     pa.field('edited',pa.bool_(),nullable=True),
 151     pa.field('time_edited',pa.timestamp('ms'),nullable=True),
 152     pa.field('subreddit_type',pa.string(),nullable=True),
 153     pa.field('subreddit_id',pa.string(),nullable=True),
 154     pa.field('subreddit_subscribers',pa.int64(),nullable=True),
 155     pa.field('name',pa.string(),nullable=True),
 156     pa.field('is_self',pa.bool_(),nullable=True),
 157     pa.field('stickied',pa.bool_(),nullable=True),
 158     pa.field('is_submitter',pa.bool_(),nullable=True),
 159     pa.field('quarantine',pa.bool_(),nullable=True),
 160     pa.field('error',pa.string(),nullable=True)])
 161
 162 with  pq.ParquetWriter("/gscratch/comdata/output/reddit_submissions.parquet_temp",schema=schema,compression='snappy',flavor='spark') as writer:
 163     while True:
 164         chunk = islice(rows,N)
 165         pddf = pd.DataFrame(chunk, columns=schema.names)
 166         table = pa.Table.from_pandas(pddf,schema=schema)
 167         if table.shape[0] == 0:
 168             break
 169         writer.write_table(table)
 170
 171     writer.close()
 172