From: Nate E TeBlunthuis Date: Tue, 20 Apr 2021 18:34:36 +0000 (-0700) Subject: calculate some user-level attributes to detect bots X-Git-Url: https://code.communitydata.science/cdsc_reddit.git/commitdiff_plain/ac06a8757ae1258d5357e8cefbcf3db9f7f3081d calculate some user-level attributes to detect bots --- diff --git a/bots/good_bad_bot.py b/bots/good_bad_bot.py new file mode 100644 index 0000000..eb57ff1 --- /dev/null +++ b/bots/good_bad_bot.py @@ -0,0 +1,74 @@ +from pyspark.sql import functions as f +from pyspark.sql import SparkSession +from pyspark.sql import Window +from pyspark.sql.types import FloatType +import zlib + +def zlib_entropy_rate(s): + sb = s.encode() + if len(sb) == 0: + return None + else: + return len(zlib.compress(s.encode(),level=6))/len(s.encode()) + +zlib_entropy_rate_udf = f.udf(zlib_entropy_rate,FloatType()) + +spark = SparkSession.builder.getOrCreate() + +df = spark.read.parquet("/gscratch/comdata/output/reddit_comments_by_author.parquet",compression='snappy') + +df = df.withColumn("saidbot",f.lower(f.col("body")).like("%bot%")) + +# df = df.filter(df.subreddit=='seattle') +# df = df.cache() +botreplies = df.filter(f.lower(df.body).rlike(".*[good|bad] bot.*")) +botreplies = botreplies.select([f.col("parent_id").substr(4,100).alias("bot_comment_id"),f.lower(f.col("body")).alias("good_bad_bot"),f.col("link_id").alias("gbbb_link_id")]) +botreplies = botreplies.groupby(['bot_comment_id']).agg(f.count('good_bad_bot').alias("N_goodbad_votes"), + f.sum((f.lower(f.col('good_bad_bot')).like('%good bot%').astype("double"))).alias("n_good_votes"), + f.sum((f.lower(f.col('good_bad_bot')).like('%bad bot%').astype("double"))).alias("n_bad_votes")) + +comments_by_author = df.select(['author','id','saidbot']).groupBy('author').agg(f.count('id').alias("N_comments"), + f.mean(f.col('saidbot').astype("double")).alias("prop_saidbot"), + f.sum(f.col('saidbot').astype("double")).alias("n_saidbot")) + +# pd_comments_by_author = comments_by_author.toPandas() +# pd_comments_by_author['frac'] = 500 / pd_comments_by_author['N_comments'] +# pd_comments_by_author.loc[pd_comments_by_author.frac > 1, 'frac'] = 1 +# fractions = pd_comments_by_author.loc[:,['author','frac']] +# fractions = fractions.set_index('author').to_dict()['frac'] + +# sampled_author_comments = df.sampleBy("author",fractions).groupBy('author').agg(f.concat_ws(" ", f.collect_list('body')).alias('comments')) +df = df.withColumn("randn",f.randn(seed=1968)) + +win = Window.partitionBy("author").orderBy("randn") + +df = df.withColumn("randRank",f.rank().over(win)) +sampled_author_comments = df.filter(f.col("randRank") <= 1000) +sampled_author_comments = sampled_author_comments.groupBy('author').agg(f.concat_ws(" ", f.collect_list('body')).alias('comments')) + +author_entropy_rates = sampled_author_comments.select(['author',zlib_entropy_rate_udf(f.col('comments')).alias("entropy_rate")]) + +parents = df.join(botreplies, on=df.id==botreplies.bot_comment_id,how='right_outer') + +win1 = Window.partitionBy("author") +parents = parents.withColumn("first_bot_reply",f.min(f.col("CreatedAt")).over(win1)) + +first_bot_reply = parents.filter(f.col("first_bot_reply")==f.col("CreatedAt")) +first_bot_reply = first_bot_reply.withColumnRenamed("CreatedAt","FB_CreatedAt") +first_bot_reply = first_bot_reply.withColumnRenamed("id","FB_id") + +comments_since_first_bot_reply = df.join(first_bot_reply,on = 'author',how='right_outer').filter(f.col("CreatedAt")>=f.col("first_bot_reply")) +comments_since_first_bot_reply = comments_since_first_bot_reply.groupBy("author").agg(f.count("id").alias("N_comments_since_firstbot")) + +bots = parents.groupby(['author']).agg(f.sum('N_goodbad_votes').alias("N_goodbad_votes"), + f.sum(f.col('n_good_votes')).alias("n_good_votes"), + f.sum(f.col('n_bad_votes')).alias("n_bad_votes"), + f.count(f.col('author')).alias("N_bot_posts")) + +bots = bots.join(comments_by_author,on="author",how='left_outer') +bots = bots.join(comments_since_first_bot_reply,on="author",how='left_outer') +bots = bots.join(author_entropy_rates,on='author',how='left_outer') + +bots = bots.orderBy("N_goodbad_votes",ascending=False) +bots = bots.repartition(1) +bots.write.parquet("/gscratch/comdata/output/reddit_good_bad_bot.parquet",mode='overwrite')