diff xena_query.py @ 0:8bb037f88ed2

Uploaded

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xena_query.py	Tue Jan 13 23:37:23 2015 -0500
@@ -0,0 +1,157 @@
+"""
+Utilities for xena queries.
+
+A basic query example.
+Queries are scheme expressions.
+
+>>> import xena_query as xena
+>>> xena.post("https://genome-cancer.ucsc.edu/proj/public/xena", "(+ 1 2)")
+'3.0'
+
+>>> xena.post("https://genome-cancer.ucsc.edu/proj/public/xena", "(let [x 2 y (+ x 3)] (* x y))")
+'10.0'
+
+Looking up sample ids for the TCGA LGG cohort.
+
+>>> r = xena.post("https://genome-cancer.ucsc.edu/proj/public/xena",
+                  xena.patient_to_sample_query("TCGA.LGG.sampleMap",
+                                               ["TCGA-CS-4938",
+                                                "TCGA-HT-7693",
+                                                "TCGA-CS-6665",
+                                                "TCGA-S9-A7J2",
+                                                "TCGA-FG-A6J3"]))
+'{"TCGA.LGG.sampleMap":["TCGA-CS-4938-01","TCGA-CS-6665-01","TCGA-FG-A6J3-01","TCGA-HT-7693-01","TCGA-S9-A7J2-01"]}'
+
+>>> r = xena.post("https://genome-cancer.ucsc.edu/proj/public/xena",
+                  xena.find_sample_by_field_query("TCGA.LGG.sampleMap",
+                                                    "_PATIENT",
+                                                    ["TCGA-CS-4938",
+                                                     "TCGA-HT-7693",
+                                                     "TCGA-CS-6665",
+                                                     "TCGA-S9-A7J2",
+                                                     "TCGA-FG-A6J3"]))
+'{"TCGA.LGG.sampleMap":["TCGA-CS-4938-01","TCGA-CS-6665-01","TCGA-FG-A6J3-01","TCGA-HT-7693-01","TCGA-S9-A7J2-01"]}'
+>>> import json
+>>> json.loads(r)
+{u'TCGA.LGG.sampleMap': [u'TCGA-CS-4938-01', u'TCGA-CS-6665-01', u'TCGA-FG-A6J3-01', u'TCGA-HT-7693-01', u'TCGA-S9-A7J2-01']}
+"""
+
+import urllib2
+import re
+
+def compose1(f, g):
+    def composed(*args, **kwargs):
+        return f(g(*args, **kwargs))
+    return composed
+
+# funcitonal composition, e.g.
+# compose(f, g)(a, ...) == f(g(a, ...))
+compose = lambda *funcs: reduce(compose1, funcs)
+
+def quote(s):
+    return '"' + s + '"'
+
+def array_fmt(l):
+    return '[' + ', '.join((quote(s) for s in l)) + ']'
+
+# The strategy here is
+#   o Do table scan on code to find codes matching field values
+#   o Do IN query on unpack(field, x) to find rows matching codes
+#   o Project to unpack(sample, x) to get sampleID code
+#   o Join with code to get sampleID values
+#
+# Note the :limit on the table scan. This makes the table scan exit after we've
+# found enough values, rather than continuing to the end. We can do this because
+# enumerated values are unique. An alternative would be to index all the enumerated
+# values in the db.
+sample_query_str = """
+(let [cohort %s
+      field_id-dataset (car (query {:select [[:field.id :field_id] [:dataset.id :dataset]]
+                                    :from [:dataset]
+                                    :join [:field [:= :dataset_id :dataset.id]]
+                                    :where [:and [:= :cohort cohort]
+                                                 [:= :field.name %s]]}))
+      values %s
+      field_id (:field_id field_id-dataset)
+      dataset (:dataset field_id-dataset)
+      sample (:id (car (query {:select [:field.id]
+                               :from [:field]
+                               :where [:and [:= :dataset_id dataset]
+                                            [:= :field.name "sampleID"]]})))
+      N (- (:rows (car (query {:select [:rows]
+                               :from [:dataset]
+                               :where [:= :id dataset]}))) 1)]
+  {cohort (map :value (query {:select [:value]
+                              :from [{:select [:x #sql/call [:unpack field_id, :x]]
+                                      :from [#sql/call [:system_range 0 N]]
+                                      :where [:in #sql/call [:unpack field_id, :x] {:select [:ordering]
+                                                                                             :from [:code]
+                                                                                             :where [:and [:= :field_id field_id]
+                                                                                                          [:in :value values]]
+                                                                                             :limit (count values)}]}]
+                              :join [:code [:and [:= :field_id sample]
+                                                 [:= :ordering #sql/call [:unpack sample :x]]]]}))})
+"""
+
+cohort_query_str = """
+(map :cohort (query {:select [:%distinct.cohort]
+                     :from [:dataset]
+                     :where [:not [:is nil :cohort]]}))
+"""
+
+datasets_list_in_cohort_query = """
+(map :text (query {:select [:text]
+                   :from [:dataset]
+                   :where [:= :cohort %s ]})
+"""
+
+datasets_type_pattern_str = """
+(map :name (query {:select [:name]
+                   :from [:dataset]
+                   :where [:and [:= :type %s]
+                                [:like :name %s]]}))
+"""
+
+def find_sample_by_field_query(cohort, field, values):
+    """Return a xena query which looks up sample ids for the given field=values."""
+    return sample_query_str % (quote(cohort), quote(field), array_fmt(values))
+
+def patient_to_sample_query(cohort, patients):
+    """Return a xena query which looks up sample ids for the given patients."""
+    return find_sample_by_field_query(cohort, "_PATIENT", patients)
+
+headers = { 'Content-Type' : "text/plain" }
+
+def post(url, query):
+    """POST a xena data query to the given url."""
+    req = urllib2.Request(url + '/data/', query, headers)
+    response = urllib2.urlopen(req)
+    result = response.read()
+    return result
+
+def find_cohorts():
+    """ Return a list of cohorts on a host at a specific url """
+    """ return example: ["chinSF2007_public","TCGA.BRCA.sampleMap","cohort3"] """
+    return cohort_query_str
+
+def find_datasets_in_cohort(url, cohort):
+    """ Return a list of datasets in a specific cohort on server=url.
+    Each dataset is a dictionary of the data's metadata.
+    This should be refactored to be consistent with the other methods."""
+    return map(json.loads,
+            json.loads(post(url, datasets_list_in_cohort_query % (quote(cohort)))))
+
+def find_datasets_type_pattern(type, pattern):
+    """Return a xena query which returns a list of datasets
+    filtered by a pattern on the dataset name. The pattern is sql:
+    % is wildcard."""
+    return datasets_type_pattern_str % (quote(type), quote(pattern))
+
+
+def strip_first_url_dir(path):
+    return re.sub(r'^[^/]*', '', path)
+
+# proj/<proj>/xena/<proj>/<path>
+# download/<proj>/xena/<path>
+def name_to_url(base_url, name):
+    return base_url.replace('/proj/', '/download/') + strip_first_url_dir(name)