Fixed #4

Author: flacle

README.md

@@ -9,20 +9,34 @@ Code churn has several definitions, the one that to me provides the most value a
 
 Solutions that I've found online looked at changes to files irrespective whether these are new changes or edits to existing lines of code (LOC) within existing files. Hence this solution that segments line-of-code edits (churn) with new code changes (contribution).
 
+*Tested with Python version 3.5.3 and Git version 2.20.1*
+
 # How it works
 This script looks at a range of commits per author. For each commit it bookkeeps the files that were changed along with the LOC for each file. LOC are kept in a sparse structure and changes per LOC are taken into account as the program loops. When a change to the same LOC is detected it updates this separately to bookkeep the true code churn.
 Result is a print with aggregated contribution and churn per author for a given time period.
 
-Tested with Python version 3.5.3 and Git version 2.20.1
+***Note:*** This includes the `--no-merges` flag as it assumes that merge commits with or without merge conflicts are not indicative of churn.
 
 # Usage
+Positional (required) arguments:
+- **after**        after a certain date, in YYYY[-MM[-DD]] format
+- **before**     before a certain date, in YYYY[-MM[-DD]] format
+- **author**     author string (not committer)
+- **dir**            include Git repository directory
+
+Optional arguments:
+- **-h, --h, --help**    show this help message and exit
+- **-exdir**                   exclude Git repository subdirectory
+
+## Example
 ```bash
-python ./gitcodechurn.py before="2019-03-01" after="2018-11-29" author="an author" dir="/Users/myname/myrepo" -exdir="excluded-directory"
+python ./gitcodechurn.py after="2018-11-29" before="2019-03-01" author="an author" dir="/Users/myname/myrepo" -exdir="excluded-directory"
 ```
-# Output
+## Output
 ```bash
-contribution:  844
-churn:  -28
+author:       an author
+contribution: 844
+churn:        -28
 ```
 Outputs can be used as part of a pipeline that generates bar charts for reports:
 ![contribution vs churn example chart](/chart.png)

gitcodechurn.py

@@ -35,18 +35,18 @@
 def main():
     parser = argparse.ArgumentParser(
         description = 'Compute true git code churn to understand tech debt.',
-        usage       = 'python [*/]gitcodechurn.py before="YYYY-MM-DD" after="YYYY-MM-DD" author="flacle" dir="[*/]path" [-exdir="[*/]path"] [-h]',
+        usage       = 'python [*/]gitcodechurn.py after="YYYY[-MM[-DD]]" before="YYYY[-MM[-DD]]" author="flacle" dir="[*/]path" [-exdir="[*/]path"]',
         epilog      = 'Feel free to fork at or contribute on: https://github.com/flacle/truegitcodechurn'
     )
     parser.add_argument(
-        'before',
+        'after',
         type = str,
-        help = 'before a certain date, in YYYY-MM-DD format'
+        help = 'after a certain date, in YYYY[-MM[-DD]] format'
     )
     parser.add_argument(
-        'after',
+        'before',
         type = str,
-        help = 'after a certain date, in YYYY-MM-DD format'
+        help = 'before a certain date, in YYYY[-MM[-DD]] format'
     )
     parser.add_argument(
         'author',
@@ -68,17 +68,17 @@ def main():
     )
     args = parser.parse_args()
 
-    before = args.before
     after  = args.after
+    before = args.before
     author = args.author
     dir    = args.dir
     # exdir is optional
     exdir  = args.exdir
 
     # for the positionals we remove the prefixes
     # TODO not sure why this is happening
-    before  = remove_prefix(before, 'before=')
     after   = remove_prefix(after, 'after=')
+    before  = remove_prefix(before, 'before=')
     author  = remove_prefix(author, 'author=')
     # dir is already handled in dir_path()
 
@@ -100,8 +100,9 @@ def main():
             exdir
         )
 
-    print('contribution: ', contribution)
-    print('churn: ', -churn)
+    print('author: \t', author)
+    print('contribution: \t', contribution)
+    print('churn: \t\t', -churn)
     # print files in case more granular results are needed
     #print('files: ', files)
 
@@ -220,7 +221,7 @@ def dir_path(path):
     if os.path.isdir(path):
         return path
     else:
-        raise argparse.ArgumentTypeError("Directory "+path+" is not a valid path.")
+        raise argparse.ArgumentTypeError(path + " is not a valid path.")
 
 #https://stackoverflow.com/a/16891418
 def remove_prefix(text, prefix):