-
Notifications
You must be signed in to change notification settings - Fork 18
/
group_by.clj
214 lines (184 loc) · 8.26 KB
/
group_by.clj
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
(ns tablecloth.api.group-by
(:refer-clojure :exclude [group-by])
(:require [tech.v3.dataset :as ds]
[tech.v3.dataset.column :as col]
[tech.v3.datatype :as dtype]
[tablecloth.api.utils :refer [iterable-sequence? ->str column-names parallel-concat grouped? mark-as-group map-inst?]]
[tablecloth.api.dataset :refer [dataset]]))
(defn- find-group-indexes
"Calulate indexes for groups"
[ds grouping-selector selected-keys]
(cond
(map-inst? grouping-selector) grouping-selector
(iterable-sequence? grouping-selector) (ds/group-by->indexes
(ds/select-columns ds (column-names ds grouping-selector)) identity)
(fn? grouping-selector) (ds/group-by->indexes
(ds/select-columns ds (column-names ds selected-keys)) grouping-selector)
:else (ds/group-by-column->indexes ds grouping-selector)))
(defn- subdataset
[ds id k idxs]
(-> ds
(ds/select :all idxs)
(ds/set-dataset-name (str "Group: " k))
(vary-meta assoc :group-id id)))
(defn- group-indexes->map
"Create map representing grouped dataset from indexes"
[ds id [k idxs]]
{:name k
:group-id id
:data (subdataset ds id k idxs)})
(defn- group-by->dataset
"Create grouped dataset from indexes"
[ds group-indexes options]
(-> (map-indexed (partial group-indexes->map ds) group-indexes)
(dataset options)
(mark-as-group)))
;; TODO: maybe make possible nested grouping and ungrouping?
(defn group-by
"Group dataset by:
- column name
- list of columns
- map of keys and row indexes
- function getting map of values
Options are:
- select-keys - when grouping is done by function, you can limit fields to a `select-keys` seq.
- result-type - return results as dataset (`:as-dataset`, default) or as map of datasets (`:as-map`) or as map of row indexes (`:as-indexes`) or as sequence of (sub)datasets
- other parameters which are passed to `dataset` fn
When dataset is returned, meta contains `:grouped?` set to true. Columns in dataset:
- name - group name
- group-id - id of the group (int)
- data - group as dataset"
([ds grouping-selector] (group-by ds grouping-selector nil))
([ds grouping-selector {:keys [select-keys result-type]
:or {result-type :as-dataset select-keys :all}
:as options}]
(let [selected-keys (column-names ds select-keys)
group-indexes (find-group-indexes ds grouping-selector selected-keys)]
(condp = result-type
:as-indexes group-indexes
:as-seq (->> group-indexes ;; java.util.HashMap
(map-indexed (fn [id [k idxs]] (subdataset ds id k idxs))))
:as-map (->> group-indexes ;; java.util.HashMap
(map-indexed (fn [id [k idxs]] [k (subdataset ds id k idxs)]))
(into {}))
(group-by->dataset ds group-indexes options)))))
(defn groups->map
"Convert grouped dataset to the map of groups"
[ds]
(assert (grouped? ds) "Apply on grouped dataset only")
(zipmap (ds :name) (ds :data)))
(defn groups->seq
[ds]
(assert (grouped? ds) "Apply on grouped dataset only")
(seq (ds :data)))
;; ungrouping
(defn- add-groups-as-columns
"Add group columns to the result of ungrouping"
[ds col1 col2 columns]
(->> columns
(clojure.core/concat col1 col2)
(remove nil?)
(ds/new-dataset)
(assoc ds :data)))
(defn- group-name-map->cols
"create columns with repeated value `v` from group name if it's map."
[name count]
(->> name
(repeat count)
(ds/->dataset)
(ds/columns)))
(defn- maybe-name
[possible-name default-name]
(if (true? possible-name)
default-name
possible-name))
(defn- group-name-seq->map
[name add-group-as-column]
(let [cn (if (iterable-sequence? add-group-as-column)
add-group-as-column
(let [tn (maybe-name add-group-as-column :$group-name)]
(map-indexed #(keyword (str %2 "-" %1)) (repeat (->str tn)))))]
(zipmap cn name)))
(defn- group-name-seq->cols
[name add-group-as-column count]
(-> name
(group-name-seq->map add-group-as-column)
(group-name-map->cols count)))
(defn- group-as-column->seq
"Convert group name to a seq of columns"
[add-group-as-column separate? name count]
(when add-group-as-column
(cond
(and separate? (map? name)) (group-name-map->cols name count)
(and separate? (iterable-sequence? name)) (group-name-seq->cols name add-group-as-column count)
:else [(col/new-column (maybe-name add-group-as-column :$group-name) (repeat count name))])))
(defn- group-id-as-column->seq
"Convert group id to as seq of columns"
[add-group-id-as-column count group-id]
(when add-group-id-as-column
[(col/new-column (maybe-name add-group-id-as-column :$group-id) (dtype/const-reader group-id count))]))
(defn- prepare-ds-for-ungrouping
"Add optional group name and/or group-id as columns to a result of ungrouping."
[ds add-group-as-column add-group-id-as-column separate? parallel?]
(let [mapper (if parallel? pmap map)]
(->> ds
(ds/mapseq-reader)
(mapper (fn [{:keys [name group-id data] :as ds}]
(if (or add-group-as-column
add-group-id-as-column)
(let [count (ds/row-count data)]
(add-groups-as-columns ds
(group-as-column->seq add-group-as-column separate? name count)
(group-id-as-column->seq add-group-id-as-column count group-id)
(ds/columns data)))
ds))))))
(defn- order-ds-for-ungrouping
"Order results by group name or leave untouched."
[prepared-ds order-by-group?]
(cond
(= :desc order-by-group?) (sort-by :name #(compare %2 %1) prepared-ds)
order-by-group? (sort-by :name prepared-ds)
:else prepared-ds))
(defn ungroup
"Concat groups into dataset.
When `add-group-as-column` or `add-group-id-as-column` is set to `true` or name(s), columns with group name(s) or group id is added to the result.
Before joining the groups groups can be sorted by group name."
([ds] (ungroup ds nil))
([ds {:keys [order? add-group-as-column add-group-id-as-column separate? dataset-name parallel?]
:or {separate? true}}]
(assert (grouped? ds) "Works only on grouped dataset")
(let [concatter (if parallel? parallel-concat ds/concat)]
(-> ds
(prepare-ds-for-ungrouping add-group-as-column add-group-id-as-column separate? parallel?)
(order-ds-for-ungrouping order?)
(->> (map :data)
(apply concatter))
(ds/set-dataset-name (or dataset-name (ds/dataset-name ds)))))))
;; processing and ungrouping in-place
;; instead of creating subdatasets create seq of maps
(defn- add-groups-to-a-map
"Convert group name to a seq of columns"
[curr-row add-group-as-column separate? name]
(cond
(and separate? (map? name)) (concat name curr-row)
(and separate? (iterable-sequence? name)) (concat (group-name-seq->map name add-group-as-column) curr-row)
:else (conj curr-row [(maybe-name add-group-as-column :$group-name) name])))
(defn- process-and-ungroup
[ds process-fn add-group-as-column add-group-id-as-column separate? parallel?]
(let [mapper (if parallel? pmap map)]
(->> ds
(ds/mapseq-reader)
(mapper (fn [{:keys [name group-id data]}]
(into (array-map) (cond-> (process-fn data)
add-group-id-as-column (conj [(maybe-name add-group-id-as-column :$group-id) group-id])
add-group-as-column (add-groups-to-a-map add-group-as-column separate? name))))))))
(defn process->ungroup
([ds process-fn] (process->ungroup ds process-fn nil))
([ds process-fn {:keys [order? add-group-as-column add-group-id-as-column separate? dataset-name parallel?]
:or {separate? true}}]
(assert (grouped? ds) "Works only on grouped dataset")
(-> ds
(order-ds-for-ungrouping order?)
(process-and-ungroup process-fn add-group-as-column add-group-id-as-column separate? parallel?)
(dataset)
(ds/set-dataset-name (or dataset-name (ds/dataset-name ds))))))