initial commit

Generate_cDNA.py

+#!/usr/bin/env python3
+#Author: Suvarnan Selliah
+
+class GeneratecDNA:
+
+    def generatecDNA(fasta, gtf, cp_nr, my_output_fasta="cDNA.fasta", my_output_csv="cDNA.csv", placeholder = "ph-file.csv"):
+
+        cDNA_transcript_id = 1
+        #READING INPUT FILES / PART I
+        #open files
+        with open(fasta, 'r') as fa, open(gtf, 'r') as gt, open(cp_nr, 'r') as cp:
+
+            #read fasta-file
+            for myFastaline in fa:
+
+                #search for transcript id and transcript sequence in fasta-file
+                fasta_id = ""
+                fasta_seq = ""
+                fasta_id_found = False
+                fasta_seq_found = False
+                currentFastaString = myFastaline
+                if fasta_id_found == False:
+                    position_of_start = currentFastaString.find('>')
+                    if position_of_start != 0:
+                        continue
+                    elif position_of_start == 0:
+                        fasta_id = myFastaline
+                        fasta_id = fasta_id.replace(">", "")
+                        fasta_id_found = True
+                        continue
+                    else:
+                        print("FASTA: Start position in fasta file not found")
+                        break
+                if fasta_id_found == True and fasta_seq_found == False:
+                    while fasta_seq_found == False:
+                        currentFastaString = fa.readline()
+                        zero_position = currentFastaString[0]
+                        if zero_position == ";":
+                            continue
+                        elif zero_position == ">":
+                            print("FASTA: No Sequence after headline")
+                            break
+                        else:
+                            fasta_seq = currentFastaString
+                            fasta_seq_found = True
+
+                #starting to work with gtf-file
+                #defining variables for gtf-file
+                gtf_seqname = ''
+                gtf_start = 0
+                gtf_end = 0
+                gtf_score = 0.0
+                gtf_info_found = False
+                gtf_entries = 0
+                gtf_list_of_lines = []
+                gtf_prob_list = []
+
+                #defining variables for csv-file
+                csv_trans_id = ""
+                csv_gene_id = ""
+                csv_count = 0
+                csv_info_found = False
+
+                if fasta_id_found == True and fasta_seq_found == True:
+                    # search for transcript id from fasta-file in gtf-file
+                    for myGTFline in gt:
+                        currentGTFString = myGTFline
+                        gtf_list = currentGTFString.split('\t')
+                        gtf_seqname = gtf_list[0]
+                        if gtf_seqname == fasta_id:
+                            gtf_entries += 1
+                            gtf_start = gtf_list[3]
+                            gtf_end = gtf_list[4]
+                            gtf_score = gtf_list[5]
+                            gtf_temp_list = []
+                            gtf_temp_list.append(gtf_start)
+                            gtf_temp_list.append(gtf_end)
+                            gtf_temp_list.append(gtf_score)
+                            gtf_list_of_lines.append(gtf_temp_list)
+                            gtf_prob_list.append(gtf_score)
+                        else:
+                            continue
+                    if gtf_entries != 0:
+                        gtf_info_found = True
+                        fasta_id_found = False
+                        fasta_seq_found = False
+                    assert gtf_info_found, "Sequence ID from fasta-file not found in gtf-file"
+
+                    #search copy number of transcript in 3. file/csv-file
+                    for myCSVline in cp:
+                        currentCSVString = myCSVline
+                        csv_list = currentCSVString.split(',')
+                        csv_trans_id = csv_list[0]
+                        if csv_trans_id == fasta_id:
+                            csv_gene_id = csv_list[1]
+                            csv_count = csv_list[2]
+                            csv_info_found = True
+                            gtf_info_found = False
+                            break
+                        else:
+                            continue
+                    assert csv_info_found, "Data (TranscriptID,GeneID,Count) from csv-file/3.file not found"
+
+                    #COMPUTATION & OUTPUT / PART II
+                    #set score to 0 for primimg sites close to the end of sequence
+                    seq_len = len(fasta_seq)
+                    seq_len -= 22
+                    gtf_list_of_lines_len = len(gtf_list_of_lines)
+                    for i in range(gtf_list_of_lines_len):
+                        if gtf_list_of_lines[i][1] > seq_len:
+                            gtf_list_of_lines[i][2] = 0.0
+                            gtf_prob_list[i] = 0.0
+
+                    #assign priming sites (according to score) to copy number
+                    sum_of_score = 0.0
+                    for i in gtf_prob_list:
+                        sum_of_score += i
+                    one_score = 100/sum_of_score
+                    norm_list = []
+                    gtf_prob_list_len = len(gtf_prob_list)
+                    for i in range(gtf_prob_list_len):
+                        norm_list.append((one_score * gtf_prob_list[i]))
+                    one_norm = csv_count / 100
+                    distr_RNA_to_prim_sites = []
+                    norm_list_len = len(norm_list)
+                    for i in range(norm_list_len):
+                        distr_RNA_to_prim_sites.append((one_norm * norm_list[i]))
+                    total_RNA_number = 0
+                    distr_RNA_to_prim_sites_len = len(distr_RNA_to_prim_sites)
+                    for i in range(distr_RNA_to_prim_sites_len):
+                        total_RNA_number += distr_RNA_to_prim_sites[i]
+                    new_distr_RNA_to_prim_sites = []
+                    if total_RNA_number != csv_count:
+                        for i in range(distr_RNA_to_prim_sites_len):
+                            new_distr_RNA_to_prim_sites.append(int(distr_RNA_to_prim_sites[i]))
+                    new_distr_RNA_to_prim_sites_len = len(new_distr_RNA_to_prim_sites)
+                    counter = 0
+                    while total_RNA_number != csv_count:
+                        new_distr_RNA_to_prim_sites[counter] = round(distr_RNA_to_prim_sites[counter])
+                        counter += 1
+                        assert counter <= new_distr_RNA_to_prim_sites_len, "Calculated RNA transcripts (assigned to priming sites) are more than initial count"
+
+                    #order the priming sites
+                    prim_sites_ordered = []
+                    for i in range(gtf_list_of_lines_len):
+                        prim_sites_ordered.append(gtf_list_of_lines[i][0])
+                    prim_sites_ordered.sort()
+
+                    #searching for 2 priming sites
+                    prim_sites_ordered_len = len(prim_sites_ordered)
+                    ph_1 = 0
+                    ph_2 = 0
+                    for i in range(0, (prim_sites_ordered_len-1), 2):
+                        if prim_sites_ordered[i] == 0.0:
+                            continue
+                        else:
+                            search_for_1 = prim_sites_ordered[i]
+                            search_for_2 = prim_sites_ordered[i+1]
+                            for j in range(gtf_list_of_lines_len):
+                                if gtf_list_of_lines[j][0] == search_for_1:
+                                    ph_1 = j
+                                if gtf_list_of_lines[j][0] == search_for_2:
+                                    ph_2 = j
+                            #making cDNA and comparing in library
+                            start_1 = gtf_list_of_lines[ph_1][0]
+                            start_2 = gtf_list_of_lines[ph_2][0]
+                            start_1 -= 1
+                            start_2 -= 1
+                            trans_between_prim_sites = fasta_seq[start_1:start_2]
+                            cDNA = ''
+                            for element in range(0, len(trans_between_prim_sites)):
+                                if trans_between_prim_sites[element] == 'A':
+                                    cDNA[element] = 'T'
+                                elif trans_between_prim_sites[element] == 'U':
+                                    cDNA[element] = 'A'
+                                elif trans_between_prim_sites[element] == 'G':
+                                    cDNA[element] = 'C'
+                                elif trans_between_prim_sites[element] == 'C':
+                                    cDNA[element] = 'G'
+                                else:
+                                    assert False, "cDNA synthesis failed, position is not A,U,G or C in transcript"
+                            # open output files
+                            if i == 0:
+                                with open(my_output_fasta, 'a') as myfasta, open(my_output_csv, 'a') as mycsv:
+                                    myfasta.write(">" + string(cDNA_transcript_id))
+                                    myfasta.write("\n")
+                                    myfasta.write(cDNA)
+                                    mycsv.write(",".join([cDNA_transcript_id, csv_gene_id, new_distr_RNA_to_prim_sites[ph_1]]))
+                            else:
+                                found_cDNA_id = ''
+                                found_cDNA_id_bool = False
+                                with open(my_output_fasta, 'r') as myfasta, open(my_output_csv, 'r') as mycsv, open(placeholder, 'w') as phf:
+                                    for myline in myfasta:
+                                        pos = myline.find('>')
+                                        if pos != 0:
+                                            continue
+                                        if pos == 0:
+                                            fid = myline
+                                            fid = fid.replace(">", "")
+                                            fbool = False
+                                            while fbool == False:
+                                                myline = myfasta.readline()
+                                                zer = myline[0]
+                                                if zer == ";":
+                                                    continue
+                                                elif zer == ">":
+                                                    assert False, "Error in searching cDNA in output fasta-file"
+                                                else:
+                                                    fseq = myline
+                                                    fbool = True
+                                            if fseq ==cDNA:
+                                                found_cDNA_id = fid
+                                                found_cDNA_id_bool = True
+                                                break
+                                    if found_cDNA_id_bool == True:
+                                        for myline_csv_out in mycsv:
+                                            csvlist = myline_csv_out.split(',')
+                                            csvcDNAid = csvlist[0]
+                                            if csvcDNAid == found_cDNA_id:
+                                                csvgeneid = csvlist[1]
+                                                csvcDNAcount = csvlist[2]
+                                                csvcDNAcount += new_distr_RNA_to_prim_sites[ph_1]
+                                                phf.write(",".join([csvcDNAid, csvgeneid, csvcDNAcount]))
+                                            else:
+                                                phf.write(myline_csv_out)
+                                if found_cDNA_id_bool == True:
+                                    with open(my_output_csv, 'w') as mycsv, open(placeholder, 'r') as phf:
+                                        for myplaceholder in phf:
+                                            mycsv.write(myplaceholder)
+                                else:
+                                    cDNA_transcript_id += 1
+                                    with open(my_output_fasta, 'a') as myfasta, open(my_output_csv, 'a') as mycsv:
+                                        myfasta.write(">" + string(cDNA_transcript_id))
+                                        myfasta.write("\n")
+                                        myfasta.write(cDNA)
+                                        mycsv.write(",".join(
+                                            [cDNA_transcript_id, csv_gene_id, new_distr_RNA_to_prim_sites[ph_1]]))
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