minor changes based on pylint

gtf_processing/pre_bedtools.py

-import pandas as pd
-import argparse
-from gtfparse import read_gtf
-
 """This script defines a BED from exon annotation in a GTF, to get exon coordinates for use in bedtools. It also ensures that the concatenation happens in the correct order, regardless of the strandedness of the transcript.
 
     Args:
@@ -11,6 +7,10 @@ from gtfparse import read_gtf
         BED file with the format: chr, start, end, transcript_id, score, strand, gene_id
 """
 
+import argparse
+import pandas as pd
+from gtfparse import read_gtf
+
 parser = argparse.ArgumentParser(
     prog = 'pre_bedtools',
     description = 'extracts ordered information from gtf file and for transcripts in the negative strand, flips the order in which exons are ordered.')
@@ -31,4 +31,3 @@ gtf_df_pos = gtf_exons[gtf_exons["strand"] == "+"]
 gtf_df_pos = gtf_df_pos.sort_values(['transcript_id','start'],ascending=True).groupby('transcript_id').head(len(gtf_df_pos. transcript_id))
 
 pd.concat([gtf_df_pos, gtf_df_neg]).to_csv(args.output_bed_file,sep="\t",index=False) #gtf_df_pos and gtf_df_neg must be dataframes
-