diff --git a/s7.py b/s7.py
new file mode 100644
index 0000000..8914a22
--- /dev/null
+++ b/s7.py
@@ -0,0 +1,126 @@
+# -*- coding:utf-8 -*-
+'''
+Step 7
+'''
+#!/usr/bin/env python
+from __future__ import print_function
+from base import create_csv, TARGET_DIR, MODEL_LIST
+import os
+import csv
+import random
+
+'''
+แก้ตรงนี้ไปก่อนละกัน No of Tree = “4Ts” และ No of R = “5”
+
+No of Tree ของคุณ ==== NOT_ARG --- ถ้าต้องการทั้งหมดใช้ 'all'
+No of R ของคุณ ======= TOTAL -- ถ้าต้องการทั้งหมดก็ = 0
+แต่ว่า ผมไม่รับรองว่าจะใช้ได้ทั้งหมดเพราะว่า มันก็ขึ้นกับหลายอย่าง
+เช่น 1Ts มีไม่กี่อันอาจจะ error มั้ง? โดยเฉพาะเวลา random
+'''
+NOT_ARG = '2Ts'
+TOTAL = 20
+
+SRC_PATH = os.path.join(TARGET_DIR, 'part6')
+
+
+def get_by_order():
+    for m in MODEL_LIST:
+        result = []
+        count = 0
+        with open(os.path.join(SRC_PATH, '%s-6.csv' % m), 'rb') as f:
+            rows = csv.reader(f)
+            for r in rows:
+                if NOT_ARG != r[2] and NOT_ARG != 'all':
+                    continue
+                row = [
+                    r[0],  # R_id
+                    'Ord_%s' % r[1],  # no of R
+                    r[2],  # No of Tree
+                    m,  # model
+                ] + r[7:]
+                result.append(row)
+                count += 1
+                if count >= TOTAL and TOTAL > 0:
+                    break
+
+        output_name = '%s-1.csv' % m
+        create_csv(output_name, result, directory='part7')
+
+
+def get_by_random():
+    for m in MODEL_LIST:
+        lo_list = []
+        result = []
+        with open(os.path.join(SRC_PATH, '%s-6.csv' % m), 'rb') as f:
+            rows = csv.reader(f)
+            for r in rows:
+                l = [
+                    r[0],  # R_id
+                    '',  # no of R
+                    r[2],  # No of Tree
+                    m,  # model
+                ] + r[7:]
+                lo_list.append(l)
+
+        picked = []
+        ok = False
+        _TOTAL = len(lo_list) if TOTAL < 1 else TOTAL
+        for i in xrange(0, _TOTAL):
+            ok = False
+            while not ok:
+                pick = random.choice(lo_list)
+                if NOT_ARG != pick[2] and NOT_ARG != 'all':
+                    continue
+                if pick[0] not in picked:
+                    picked.append(pick[0])
+                    pick[1] = 'Ran_%s' % i
+                    ok = True
+
+            result.append(pick)
+
+        output_name = '%s-2.csv' % m
+        create_csv(output_name, result, directory='part7')
+
+
+def get_by_group(model_name, step, **kwargs):
+    new_prefix = kwargs.get('prefix', 'XX')
+    output_suffix = kwargs.get('suffix', '3')
+
+    result = []
+    count = 1
+    fpath = os.path.join(TARGET_DIR, 'part7', '%s-%s.csv' % (model_name, step))
+    with open(fpath, 'rb') as f:
+        rows = csv.reader(f)
+        # do nothing to 1st row
+        first = rows.next()
+        first[0] = '%s_%s' % (new_prefix, count)
+        result.append(first)
+
+        calibrator = first[:]
+        for r in rows:
+            count += 1
+            _r = r[:]
+            _r[0] = '%s_%s' % (new_prefix, count)
+            for i in xrange(5, len(_r)):
+                # get rid of asterik first
+                calibrator[i] = calibrator[i].replace('*', '')
+                # do comparison
+                if _r[i] == 'Y/N' or _r[i] == calibrator[i] or calibrator[i] == '':
+                    pass
+                elif (_r[i] == '' and calibrator[i] != '') or calibrator[i] == 'Y/N':
+                    _r[i] = '%s*' % calibrator[i]
+                else:  # one Y one N
+                    _r[i] = 'Y/N*'
+            result.append(_r)
+            calibrator = _r[:]
+
+        output_name = '%s-%s.csv' % (model_name, output_suffix)
+        create_csv(output_name, result, directory='part7')
+
+
+get_by_order()
+get_by_random()
+
+for m in MODEL_LIST:
+    for s in '12':
+        get_by_group(m, s, prefix='Rg', suffix=('3' if s == '1' else '4'))