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cdsc_reddit/submissions_2_parquet_part1.py

110 lines
3.9 KiB
Python
Executable File

#!/usr/bin/env python3
# two stages:
# 1. from gz to arrow parquet (this script)
# 2. from arrow parquet to spark parquet (submissions_2_parquet_part2.py)
import json
from datetime import datetime
from multiprocessing import Pool
from itertools import islice
from helper import find_dumps, open_fileset
import pandas as pd
import pyarrow as pa
import pyarrow.parquet as pq
def parse_submission(post, names = None):
if names is None:
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']
try:
post = json.loads(post)
except (json.decoder.JSONDecodeError, UnicodeDecodeError) as e:
# print(e)
# print(post)
row = [None for _ in names]
row[-1] = "json.decoder.JSONDecodeError|{0}|{1}".format(e,post)
return tuple(row)
row = []
for name in names:
if name == 'created_utc' or name == 'retrieved_on':
val = post.get(name,None)
if val is not None:
row.append(datetime.fromtimestamp(int(post[name]),tz=None))
else:
row.append(None)
elif name == 'edited':
val = post[name]
if type(val) == bool:
row.append(val)
row.append(None)
else:
row.append(True)
row.append(datetime.fromtimestamp(int(val),tz=None))
elif name == "time_edited":
continue
elif name == 'has_media':
row.append(post.get('media',None) is not None)
elif name not in post:
row.append(None)
else:
row.append(post[name])
return tuple(row)
dumpdir = "/gscratch/comdata/raw_data/reddit_dumps/submissions"
files = list(find_dumps(dumpdir))
pool = Pool(28)
stream = open_fileset(files)
N = 100000
rows = pool.imap_unordered(parse_submission, stream, chunksize=int(N/28))
schema = pa.schema([
pa.field('id', pa.string(),nullable=True),
pa.field('author', pa.string(),nullable=True),
pa.field('subreddit', pa.string(),nullable=True),
pa.field('title', pa.string(),nullable=True),
pa.field('created_utc', pa.timestamp('ms'),nullable=True),
pa.field('permalink', pa.string(),nullable=True),
pa.field('url', pa.string(),nullable=True),
pa.field('domain', pa.string(),nullable=True),
pa.field('score', pa.int64(),nullable=True),
pa.field('ups', pa.int64(),nullable=True),
pa.field('downs', pa.int64(),nullable=True),
pa.field('over_18', pa.bool_(),nullable=True),
pa.field('has_media',pa.bool_(),nullable=True),
pa.field('selftext',pa.string(),nullable=True),
pa.field('retrieved_on', pa.timestamp('ms'),nullable=True),
pa.field('num_comments', pa.int64(),nullable=True),
pa.field('gilded',pa.int64(),nullable=True),
pa.field('edited',pa.bool_(),nullable=True),
pa.field('time_edited',pa.timestamp('ms'),nullable=True),
pa.field('subreddit_type',pa.string(),nullable=True),
pa.field('subreddit_id',pa.string(),nullable=True),
pa.field('subreddit_subscribers',pa.int64(),nullable=True),
pa.field('name',pa.string(),nullable=True),
pa.field('is_self',pa.bool_(),nullable=True),
pa.field('stickied',pa.bool_(),nullable=True),
pa.field('quarantine',pa.bool_(),nullable=True),
pa.field('error',pa.string(),nullable=True)])
with pq.ParquetWriter("/gscratch/comdata/output/reddit_submissions.parquet_temp",schema=schema,compression='snappy',flavor='spark') as writer:
while True:
chunk = islice(rows,N)
pddf = pd.DataFrame(chunk, columns=schema.names)
table = pa.Table.from_pandas(pddf,schema=schema)
if table.shape[0] == 0:
break
writer.write_table(table)
writer.close()