Create counting email in a database

Author: xchen012

counting email in a database

@@ -0,0 +1,51 @@
+import sqlite3
+
+# create a connection object that represents the database, the data will be stored in the emaildb.sqlite file.
+conn = sqlite3.connect('emaildb.sqlite')
+
+# create a cursor object and call execute() method to perform SQL commands
+cur = conn.cursor()
+
+# every time run this program, drop the table and then create it again
+cur.execute('''
+DROP TABLE IF EXISTS Counts''')
+cur.execute('''
+CREATE TABLE Counts (org TEXT, count INTEGER)''')
+
+# prompt for file name
+fname = raw_input('Enter file name: ')
+if ( len(fname) < 1 ) : fname = 'mbox-short.txt'
+fh = open(fname)
+for line in fh:
+    if not line.startswith('From: ') : continue
+    pieces = line.split()
+    email = pieces[1]
+    parts = email.split('@')
+    org = parts[1]
+    print org
+    # question maker is a place holder to be filled in
+    cur.execute('SELECT count FROM Counts WHERE org = ? ', (org, )) 
+    row = cur.fetchone()
+    if row is None:
+        cur.execute('''INSERT INTO Counts (org, count) 
+                VALUES ( ?, 1 )''', ( org, ) )
+    else : 
+        cur.execute('UPDATE Counts SET count=count+1 WHERE org = ?', 
+            (org, ))
+    # This statement commits outstanding changes to disk each 
+    # time through the loop - the program can be made faster 
+    # by moving the commit so it runs only after the loop completes
+    conn.commit()
+
+# https://www.sqlite.org/lang_select.html
+sqlstr = 'SELECT org, count FROM Counts ORDER BY count DESC LIMIT 10'
+
+print
+print "Counts:"
+for row in cur.execute(sqlstr) :
+    print str(row[0]), row[1]
+
+cur.close()
+
+
+# https://docs.python.org/2/library/sqlite3.html