diff vsnp_get_snps.py @ 0:ee4ef1fc23c6 draft

Uploaded

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vsnp_get_snps.py	Tue Apr 21 10:14:11 2020 -0400
@@ -0,0 +1,519 @@
+#!/usr/bin/env python
+
+# Collect quality parsimonious SNPs from vcf files and output alignment files in fasta format.
+
+import argparse
+import multiprocessing
+import os
+import pandas
+import queue
+import shutil
+import sys
+import time
+import vcf
+from collections import OrderedDict
+from datetime import datetime
+
+ALL_VCFS_DIR = 'all_vcf'
+INPUT_VCF_DIR = 'input_vcf_dir'
+OUTPUT_JSON_AVG_MQ_DIR = 'output_json_avg_mq_dir'
+OUTPUT_JSON_SNPS_DIR = 'output_json_snps_dir'
+OUTPUT_SNPS_DIR = 'output_snps_dir'
+
+
+def get_time_stamp():
+    return datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d %H-%M-%S')
+
+
+def set_num_cpus(num_files, processes):
+    num_cpus = int(multiprocessing.cpu_count())
+    if num_files < num_cpus and num_files < processes:
+        return num_files
+    if num_cpus < processes:
+        half_cpus = int(num_cpus / 2)
+        if num_files < half_cpus:
+            return num_files
+        return half_cpus
+    return processes
+
+
+def setup_all_vcfs(vcf_files, vcf_dirs):
+    # Create the all_vcfs directory and link
+    # all input vcf files into it for processing.
+    os.makedirs(ALL_VCFS_DIR)
+    vcf_dirs.append(ALL_VCFS_DIR)
+    for vcf_file in vcf_files:
+        file_name_base = os.path.basename(vcf_file)
+        dst_file = os.path.join(ALL_VCFS_DIR, file_name_base)
+        os.symlink(vcf_file, dst_file)
+    return vcf_dirs
+
+
+class SnpFinder:
+
+    def __init__(self, num_files, reference, excel_grouper_file,
+                 all_isolates, ac, mq_val, n_threshold, qual_threshold, output_summary):
+        self.ac = ac
+        self.all_isolates = all_isolates
+        self.all_positions = None
+        # Filter based on the contents of an Excel file.
+        self.excel_grouper_file = excel_grouper_file
+        # Use Genbank file
+        self.groups = []
+        # This will be populated from the columns
+        # in the Excel filter file if it is used.
+        self.mq_val = mq_val
+        self.n_threshold = n_threshold
+        self.qual_threshold = qual_threshold
+        self.reference = reference
+        self.start_time = get_time_stamp()
+        self.summary_str = ""
+        self.timer_start = datetime.now()
+        self.num_files = num_files
+        self.initiate_summary(output_summary)
+
+    def append_to_summary(self, html_str):
+        self.summary_str = "%s%s" % (self.summary_str, html_str)
+
+    def bin_input_files(self, filename, samples_groups_dict, defining_snps, inverted_defining_snps, found_positions, found_positions_mix):
+        sample_groups_list = []
+        table_name = self.get_base_file_name(filename)
+        try:
+            defining_snp = False
+            # Absolute positions in set union of two lists.
+            for abs_position in list(defining_snps.keys() & (found_positions.keys() | found_positions_mix.keys())):
+                group = defining_snps[abs_position]
+                sample_groups_list.append(group)
+                self.check_add_group(group)
+                if len(list(defining_snps.keys() & found_positions_mix.keys())) > 0:
+                    table_name = self.get_base_file_name(filename)
+                    table_name = '%s<font color="red">[[MIXED]]</font>' % table_name
+                self.copy_file(filename, group)
+                defining_snp = True
+            if not set(inverted_defining_snps.keys()).intersection(found_positions.keys() | found_positions_mix.keys()):
+                for abs_position in list(inverted_defining_snps.keys()):
+                    group = inverted_defining_snps[abs_position]
+                    sample_groups_list.append(group)
+                    self.check_add_group(group)
+                    self.copy_file(filename, group)
+                    defining_snp = True
+            if defining_snp:
+                samples_groups_dict[table_name] = sorted(sample_groups_list)
+            else:
+                samples_groups_dict[table_name] = ['<font color="red">No defining SNP</font>']
+        except TypeError as e:
+            msg = "<br/>Error processing file %s to generate samples_groups_dict: %s<br/>" % (filename, str(e))
+            self.append_to_summary(msg)
+            samples_groups_dict[table_name] = [msg]
+        return samples_groups_dict
+
+    def check_add_group(self, group):
+        if group not in self.groups:
+            self.groups.append(group)
+
+    def copy_file(self, filename, dir):
+        if not os.path.exists(dir):
+            os.makedirs(dir)
+        shutil.copy(filename, dir)
+
+    def decide_snps(self, filename):
+        positions_dict = self.all_positions
+        # Find the SNPs in a vcf file to produce a pandas data
+        # frame and a dictionary containing sample map qualities.
+        sample_map_qualities = {}
+        # Eliminate the path.
+        file_name_base = self.get_base_file_name(filename)
+        vcf_reader = vcf.Reader(open(filename, 'r'))
+        sample_dict = {}
+        for record in vcf_reader:
+            alt = str(record.ALT[0])
+            record_position = "%s:%s" % (str(record.CHROM), str(record.POS))
+            if record_position in positions_dict:
+                if alt == "None":
+                    sample_dict.update({record_position: "-"})
+                else:
+                    # Not sure this is the best place to capture MQM average
+                    # may be faster after parsimony SNPs are decided, but
+                    # then it will require opening the files again.
+                    # On rare occassions MQM gets called "NaN", thus passing
+                    # a string when a number is expected when calculating average.
+                    mq_val = self.get_mq_val(record.INFO, filename)
+                    if str(mq_val).lower() not in ["nan"]:
+                        sample_map_qualities.update({record_position: mq_val})
+                    # Add parameters here to change what each vcf represents.
+                    # SNP is represented in table, now how will the vcf represent
+                    # the called position alt != "None", which means a deletion
+                    # as alt is not record.FILTER, or rather passed.
+                    len_alt = len(alt)
+                    if len_alt == 1:
+                        qual_val = self.val_as_int(record.QUAL)
+                        ac = record.INFO['AC'][0]
+                        ref = str(record.REF[0])
+                        if ac == 2 and qual_val > self.n_threshold:
+                            sample_dict.update({record_position: alt})
+                        elif ac == 1 and qual_val > self.n_threshold:
+                            alt_ref = "%s%s" % (alt, ref)
+                            if alt_ref == "AG":
+                                sample_dict.update({record_position: "R"})
+                            elif alt_ref == "CT":
+                                sample_dict.update({record_position: "Y"})
+                            elif alt_ref == "GC":
+                                sample_dict.update({record_position: "S"})
+                            elif alt_ref == "AT":
+                                sample_dict.update({record_position: "W"})
+                            elif alt_ref == "GT":
+                                sample_dict.update({record_position: "K"})
+                            elif alt_ref == "AC":
+                                sample_dict.update({record_position: "M"})
+                            elif alt_ref == "GA":
+                                sample_dict.update({record_position: "R"})
+                            elif alt_ref == "TC":
+                                sample_dict.update({record_position: "Y"})
+                            elif alt_ref == "CG":
+                                sample_dict.update({record_position: "S"})
+                            elif alt_ref == "TA":
+                                sample_dict.update({record_position: "W"})
+                            elif alt_ref == "TG":
+                                sample_dict.update({record_position: "K"})
+                            elif alt_ref == "CA":
+                                sample_dict.update({record_position: "M"})
+                            else:
+                                sample_dict.update({record_position: "N"})
+                            # Poor calls
+                        elif qual_val <= 50:
+                            # Do not coerce record.REF[0] to a string!
+                            sample_dict.update({record_position: record.REF[0]})
+                        elif qual_val <= self.n_threshold:
+                            sample_dict.update({record_position: "N"})
+                        else:
+                            # Insurance -- Will still report on a possible
+                            # SNP even if missed with above statement
+                            # Do not coerce record.REF[0] to a string!
+                            sample_dict.update({record_position: record.REF[0]})
+        # Merge dictionaries and order
+        merge_dict = {}
+        # abs_pos:REF
+        merge_dict.update(positions_dict)
+        # abs_pos:ALT replacing all_positions, because keys must be unique
+        merge_dict.update(sample_dict)
+        sample_df = pandas.DataFrame(merge_dict, index=[file_name_base])
+        return sample_df, file_name_base, sample_map_qualities
+
+    def df_to_fasta(self, parsimonious_df, group):
+        # Generate SNP alignment file from the parsimonious_df
+        # data frame.
+        snps_file = os.path.join(OUTPUT_SNPS_DIR, "%s.fasta" % group)
+        test_duplicates = []
+        has_sequence_data = False
+        for index, row in parsimonious_df.iterrows():
+            for pos in row:
+                if len(pos) > 0:
+                    has_sequence_data = True
+                    break
+        if has_sequence_data:
+            with open(snps_file, 'w') as fh:
+                for index, row in parsimonious_df.iterrows():
+                    test_duplicates.append(row.name)
+                    if test_duplicates.count(row.name) < 2:
+                        print(f'>{row.name}', file=fh)
+                        for pos in row:
+                            print(pos, end='', file=fh)
+                        print("", file=fh)
+        return has_sequence_data
+
+    def find_initial_positions(self, filename):
+        # Find SNP positions in a vcf file.
+        found_positions = {}
+        found_positions_mix = {}
+        try:
+            vcf_reader = vcf.Reader(open(filename, 'r'))
+            try:
+                for record in vcf_reader:
+                    qual_val = self.val_as_int(record.QUAL)
+                    chrom = record.CHROM
+                    position = record.POS
+                    absolute_position = "%s:%s" % (str(chrom), str(position))
+                    alt = str(record.ALT[0])
+                    if alt != "None":
+                        mq_val = self.get_mq_val(record.INFO, filename)
+                        ac = record.INFO['AC'][0]
+                        len_ref = len(record.REF)
+                        if ac == self.ac and len_ref == 1 and qual_val > self.qual_threshold and mq_val > self.mq_val:
+                            found_positions.update({absolute_position: record.REF})
+                        if ac == 1 and len_ref == 1 and qual_val > self.qual_threshold and mq_val > self.mq_val:
+                            found_positions_mix.update({absolute_position: record.REF})
+                return found_positions, found_positions_mix
+            except (ZeroDivisionError, ValueError, UnboundLocalError, TypeError) as e:
+                self.append_to_summar("<br/>Error parsing record in file %s: %s<br/>" % (filename, str(e)))
+                return {'': ''}, {'': ''}
+        except (SyntaxError, AttributeError) as e:
+            self.append_to_summary("<br/>Error attempting to read file %s: %s<br/>" % (filename, str(e)))
+            return {'': ''}, {'': ''}
+
+    def gather_and_filter(self, prefilter_df, mq_averages, group_dir):
+        # Group a data frame of SNPs.
+        if self.excel_grouper_file is None:
+            filtered_all_df = prefilter_df
+            sheet_names = None
+        else:
+            # Filter positions to be removed from all.
+            xl = pandas.ExcelFile(self.excel_grouper_file)
+            sheet_names = xl.sheet_names
+            # Use the first column to filter "all" postions.
+            exclusion_list_all = self.get_position_list(sheet_names, 0)
+            exclusion_list_group = self.get_position_list(sheet_names, group_dir)
+            exclusion_list = exclusion_list_all + exclusion_list_group
+            # Filters for all applied.
+            filtered_all_df = prefilter_df.drop(columns=exclusion_list, errors='ignore')
+        json_snps_file = os.path.join(OUTPUT_JSON_SNPS_DIR, "%s.json" % group_dir)
+        parsimonious_df = self.get_parsimonious_df(filtered_all_df)
+        samples_number, columns = parsimonious_df.shape
+        if samples_number >= 4:
+            has_sequence_data = self.df_to_fasta(parsimonious_df, group_dir)
+            if has_sequence_data:
+                json_avg_mq_file = os.path.join(OUTPUT_JSON_AVG_MQ_DIR, "%s.json" % group_dir)
+                mq_averages.to_json(json_avg_mq_file, orient='split')
+                parsimonious_df.to_json(json_snps_file, orient='split')
+            else:
+                msg = "<br/>No sequence data"
+                if group_dir is not None:
+                    msg = "%s for group: %s" % (msg, group_dir)
+                self.append_to_summary("%s<br/>\n" % msg)
+        else:
+            msg = "<br/>Too few samples to build tree"
+            if group_dir is not None:
+                msg = "%s for group: %s" % (msg, group_dir)
+            self.append_to_summary("%s<br/>\n" % msg)
+
+    def get_base_file_name(self, file_path):
+        base_file_name = os.path.basename(file_path)
+        if base_file_name.find(".") > 0:
+            # Eliminate the extension.
+            return os.path.splitext(base_file_name)[0]
+        elif base_file_name.find("_") > 0:
+            # The dot extension was likely changed to
+            # the " character.
+            items = base_file_name.split("_")
+            return "_".join(items[0:-1])
+        else:
+            return base_file_name
+
+    def get_mq_val(self, record_info, filename):
+        # Get the MQ (gatk) or MQM (freebayes) value
+        # from the record.INFO component of the vcf file.
+        try:
+            mq_val = record_info['MQM']
+            return self.return_val(mq_val)
+        except Exception:
+            try:
+                mq_val = record_info['MQ']
+                return self.return_val(mq_val)
+            except Exception:
+                msg = "Invalid or unsupported vcf header %s in file: %s\n" % (str(record_info), filename)
+                sys.exit(msg)
+
+    def get_parsimonious_df(self, filtered_all_df):
+        # Get the parsimonious SNPs data frame
+        # from a data frame of filtered SNPs.
+        try:
+            ref_series = filtered_all_df.loc['root']
+            # In all_vcf root needs to be removed.
+            filtered_all_df = filtered_all_df.drop(['root'])
+        except KeyError:
+            pass
+        parsimony = filtered_all_df.loc[:, (filtered_all_df != filtered_all_df.iloc[0]).any()]
+        parsimony_positions = list(parsimony)
+        parse_df = filtered_all_df[parsimony_positions]
+        ref_df = ref_series.to_frame()
+        ref_df = ref_df.T
+        parsimonious_df = pandas.concat([parse_df, ref_df], join='inner')
+        return parsimonious_df
+
+    def get_position_list(self, sheet_names, group):
+        # Get a list of positions defined by an excel file.
+        exclusion_list = []
+        try:
+            filter_to_all = pandas.read_excel(self.excel_grouper_file, header=1, usecols=[group])
+            for value in filter_to_all.values:
+                value = str(value[0])
+                if "-" not in value.split(":")[-1]:
+                    exclusion_list.append(value)
+                elif "-" in value:
+                    try:
+                        chrom, sequence_range = value.split(":")
+                    except Exception as e:
+                        sys.exit(str(e))
+                    value = sequence_range.split("-")
+                    for position in range(int(value[0].replace(',', '')), int(value[1].replace(',', '')) + 1):
+                        exclusion_list.append(chrom + ":" + str(position))
+            return exclusion_list
+        except ValueError:
+            exclusion_list = []
+            return exclusion_list
+
+    def get_snps(self, task_queue, timeout):
+        while True:
+            try:
+                group_dir = task_queue.get(block=True, timeout=timeout)
+            except queue.Empty:
+                break
+            # Parse all vcf files to accumulate SNPs into a
+            # data frame.
+            positions_dict = {}
+            group_files = []
+            for file_name in os.listdir(os.path.abspath(group_dir)):
+                file_path = os.path.abspath(os.path.join(group_dir, file_name))
+                group_files.append(file_path)
+            for file_name in group_files:
+                try:
+                    found_positions, found_positions_mix = self.find_initial_positions(file_name)
+                    positions_dict.update(found_positions)
+                except Exception as e:
+                    self.append_to_summary("Error updating the positions_dict dictionary when processing file %s:\n%s\n" % (file_name, str(e)))
+            # Order before adding to file to match
+            # with ordering of individual samples.
+            # all_positions is abs_pos:REF
+            self.all_positions = OrderedDict(sorted(positions_dict.items()))
+            ref_positions_df = pandas.DataFrame(self.all_positions, index=['root'])
+            all_map_qualities = {}
+            df_list = []
+            for file_name in group_files:
+                sample_df, file_name_base, sample_map_qualities = self.decide_snps(file_name)
+                df_list.append(sample_df)
+                all_map_qualities.update({file_name_base: sample_map_qualities})
+            all_sample_df = pandas.concat(df_list)
+            # All positions have now been selected for each sample,
+            # so select parisomony informative SNPs.  This removes
+            # columns where all fields are the same.
+            # Add reference to top row.
+            prefilter_df = pandas.concat([ref_positions_df, all_sample_df], join='inner')
+            all_mq_df = pandas.DataFrame.from_dict(all_map_qualities)
+            mq_averages = all_mq_df.mean(axis=1).astype(int)
+            self.gather_and_filter(prefilter_df, mq_averages, group_dir)
+            task_queue.task_done()
+
+    def group_vcfs(self, vcf_files):
+        # Parse an excel file to produce a
+        # grouping dictionary for filtering SNPs.
+        xl = pandas.ExcelFile(self.excel_grouper_file)
+        sheet_names = xl.sheet_names
+        ws = pandas.read_excel(self.excel_grouper_file, sheet_name=sheet_names[0])
+        defining_snps = ws.iloc[0]
+        defsnp_iterator = iter(defining_snps.iteritems())
+        next(defsnp_iterator)
+        defining_snps = {}
+        inverted_defining_snps = {}
+        for abs_pos, group in defsnp_iterator:
+            if '!' in abs_pos:
+                inverted_defining_snps[abs_pos.replace('!', '')] = group
+            else:
+                defining_snps[abs_pos] = group
+        samples_groups_dict = {}
+        for vcf_file in vcf_files:
+            found_positions, found_positions_mix = self.find_initial_positions(vcf_file)
+            samples_groups_dict = self.bin_input_files(vcf_file, samples_groups_dict, defining_snps, inverted_defining_snps, found_positions, found_positions_mix)
+        # Output summary grouping table.
+        self.append_to_summary('<br/>')
+        self.append_to_summary('<b>Groupings with %d listed:</b><br/>\n' % len(samples_groups_dict))
+        self.append_to_summary('<table  cellpadding="5" cellspaging="5" border="1">\n')
+        for key, value in samples_groups_dict.items():
+            self.append_to_summary('<tr align="left"><th>Sample Name</th>\n')
+            self.append_to_summary('<td>%s</td>' % key)
+            for group in value:
+                self.append_to_summary('<td>%s</td>\n' % group)
+            self.append_to_summary('</tr>\n')
+        self.append_to_summary('</table><br/>\n')
+
+    def initiate_summary(self, output_summary):
+        # Output summary file handle.
+        self.append_to_summary('<html>\n')
+        self.append_to_summary('<head></head>\n')
+        self.append_to_summary('<body style=\"font-size:12px;">')
+        self.append_to_summary("<b>Time started:</b> %s<br/>" % str(get_time_stamp()))
+        self.append_to_summary("<b>Number of VCF inputs:</b> %d<br/>" % self.num_files)
+        self.append_to_summary("<b>Reference:</b> %s<br/>" % str(self.reference))
+        self.append_to_summary("<b>All isolates:</b> %s<br/>" % str(self.all_isolates))
+
+    def return_val(self, val, index=0):
+        # Handle element and single-element list values.
+        if isinstance(val, list):
+            return val[index]
+        return val
+
+    def val_as_int(self, val):
+        # Handle integer value conversion.
+        try:
+            return int(val)
+        except TypeError:
+            # val is likely None here.
+            return 0
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument('--all_isolates', action='store', dest='all_isolates', required=False, default="No", help='Create table with all isolates'),
+    parser.add_argument('--excel_grouper_file', action='store', dest='excel_grouper_file', required=False, default=None, help='Optional Excel filter file'),
+    parser.add_argument('--output_summary', action='store', dest='output_summary', help='Output summary html file'),
+    parser.add_argument('--reference', action='store', dest='reference', help='Reference file'),
+    parser.add_argument('--processes', action='store', dest='processes', type=int, help='User-selected number of processes to use for job splitting')
+
+    args = parser.parse_args()
+
+    # Initializations - TODO: should these be passed in as command line args?
+    ac = 2
+    mq_val = 56
+    n_threshold = 50
+    qual_threshold = 150
+
+    # Build the list of sample vcf files for the current run.
+    vcf_files = []
+    for file_name in os.listdir(INPUT_VCF_DIR):
+        file_path = os.path.abspath(os.path.join(INPUT_VCF_DIR, file_name))
+        vcf_files.append(file_path)
+
+    multiprocessing.set_start_method('spawn')
+    queue1 = multiprocessing.JoinableQueue()
+    num_files = len(vcf_files)
+    cpus = set_num_cpus(num_files, args.processes)
+    # Set a timeout for get()s in the queue.
+    timeout = 0.05
+
+    # Initialize the snp_finder object.
+    snp_finder = SnpFinder(num_files, args.reference, args.excel_grouper_file, args.all_isolates,
+                           ac, mq_val, n_threshold, qual_threshold, args.output_summary)
+
+    # Initialize the set of directories containiing vcf files for analysis.
+    vcf_dirs = []
+    if args.excel_grouper_file is None:
+        vcf_dirs = setup_all_vcfs(vcf_files, vcf_dirs)
+    else:
+        if args.all_isolates.lower() == "yes":
+            vcf_dirs = setup_all_vcfs(vcf_files, vcf_dirs)
+        # Parse the Excel file to detemine groups for filtering.
+        snp_finder.group_vcfs(vcf_files)
+        # Append the list of group directories created by
+        # the above call to the set of directories containing
+        # vcf files for analysis
+        group_dirs = [d for d in os.listdir(os.getcwd()) if os.path.isdir(d) and d in snp_finder.groups]
+        vcf_dirs.extend(group_dirs)
+
+    # Populate the queue for job splitting.
+    for vcf_dir in vcf_dirs:
+        queue1.put(vcf_dir)
+
+    # Complete the get_snps task.
+    processes = [multiprocessing.Process(target=snp_finder.get_snps, args=(queue1, timeout, )) for _ in range(cpus)]
+    for p in processes:
+        p.start()
+    for p in processes:
+        p.join()
+    queue1.join()
+
+    # Finish summary log.
+    snp_finder.append_to_summary("<br/><b>Time finished:</b> %s<br/>\n" % get_time_stamp())
+    total_run_time = datetime.now() - snp_finder.timer_start
+    snp_finder.append_to_summary("<br/><b>Total run time:</b> %s<br/>\n" % str(total_run_time))
+    snp_finder.append_to_summary('</body>\n</html>\n')
+    with open(args.output_summary, "w") as fh:
+        fh.write("%s" % snp_finder.summary_str)