catch bug and update README

Author: cushionbadak

README.md

@@ -1,13 +1,72 @@
 # SweepFlaw demo
+
+## Prerequisites
+### System requirement
+- git
+- make
+- clang
+- g++
+### Python requirement
+- `python >= 3.5`
+- `setuptools`
+- `torch >= 1.0` will be installed during installation process.
+
 ## Install
 ```
+# If 'position-learning' and 'position_learning' directory exists at project root,
+# erase them before install.
 make install
 ```
 ## Run Sample Scenario
 ```
 make demo
 ```
-## Run Custom Scenario
+## Custom Scenario
+### Testcase Directory Structure
+You can see the example at `demodata/TC_1204B/input` and `demodata/TC_1204B/output`.
+It should be strictly followed.
+```
+$ tree demodata/TC_1204B/input
+demodata/TC_1204B/input
+├── 1
+├── 10
+├── 11
+├── 12
+├── 13
+├── 14
+├── 2
+├── 3
+├── 4
+├── 5
+├── 6
+├── 7
+├── 8
+└── 9
+
+0 directories, 14 files
+```
+```
+$ tree demodata/TC_1204B/output
+demodata/TC_1204B/output
+├── 1
+├── 10
+├── 11
+├── 12
+├── 13
+├── 14
+├── 2
+├── 3
+├── 4
+├── 5
+├── 6
+├── 7
+├── 8
+└── 9
+
+0 directories, 14 files
+```
+As you can see, the corresponding output of the input file `input/1` is `output/1`. You can configure related setting at `src/setting.py`'s `TESTCASE_STARTNUM`, `TESTCASE_PREFIX`, and `TESTCASE_POSTFIX`.
+### Run Custom Scenario
 ```
 python3 app.py [Source File] [Input Testcase Directory] [Output Testcase Directory]
 ```

src/modifyVscm.py

@@ -5,7 +5,7 @@
 # 1. sorted vscm
 # 2. the number of line-column pair from POSLEARN_APPFILE's output.
 def applyNNResult(vscm, codeFilename):
-    pr = subprocess.Popen(['python', POSLEARN_APPFILE, codeFilename, POSLEARN_MODE], cwd=POSLEARN_PROJ_DIR, stdout=subprocess.PIPE)
+    pr = subprocess.Popen(['python3', POSLEARN_APPFILE, codeFilename, POSLEARN_MODE], cwd=POSLEARN_PROJ_DIR, stdout=subprocess.PIPE)
     pr_out, pr_err = pr.communicate()
     pr_out = pr_out.decode("utf-8") 
     rnnResult = list(set([(x.split(',')[0], x.split(',')[1]) for x in pr_out.split('\n')[1:-1]]))

src/setting.py

@@ -14,7 +14,7 @@
 INFO_PRINT      = True
 
 ### Testcase Filenames
-TESTCASE_STARTNUM=1
+TESTCASE_STARTNUM = 1
 TESTCASE_PREFIX = ''
 TESTCASE_POSTFIX = ''