Add counts by library (#16)

This is for Table 1 in the paper.

library_counts.py

@@ -0,0 +1,24 @@
+#!/usr/bin/env python3
+
+import sqlite3
+
+con = sqlite3.connect("results.sqlite3")
+cur = con.cursor()
+
+def counts(table, fnc):
+  filter = "original<>changed" if fnc else "original=changed"
+  cur.execute(
+    f"""
+      select a,b, count(distinct original) from {table} where {filter} group by a,b
+    """
+  )
+  return cur.fetchall()
+
+
+print("Number of libraries by predictor and filename cases")
+print("-" * 70)
+for t in ("two_predictors", "three_predictors"):
+  for fnc in (True, False):
+    print("{0:s} {1:s}changed".format(t, "" if fnc else "un"))
+    for r in counts(t,fnc):
+      print("  ", r)