Add script and functions annotation.

Author: phcoding

jpb.py

@@ -1,9 +1,31 @@
 #!/usr/bin/env python3
 
+'''
+    Auto compile or execute java project by setting root mark file and given java 
+    file path.
+
+    Usage:
+        `python3 jpb.py [-c|-e] target_file_name`
+        `-c` means compiling mode.
+        `-e` means executing mode.
+'''
+
 import os
 import sys
 
 def find_project_root(project_file, filepath):
+    '''
+        Find project root dir accroding to mark-file name and given java file path.
+
+    Args:
+        project_file [str]  project root mark file `java.project`.You need to create
+         it in root dir.
+
+        filepth     [str]   target compile or execute java file. The script will start
+        to find mark-file from its parent dir.
+
+    return: [str] project root dir.
+    '''
     def forward_walk(filepath):
         dirname = os.path.dirname(filepath)
         if dirname != os.path.join(os.path.splitdrive(dirname)[0], os.path.sep):
@@ -17,18 +39,48 @@ def forward_walk(filepath):
     return project_root
 
 def compile_class_file(project_root, classpath):
+    '''
+        Compile java file associated with given classpath to class file.
+    
+    Args:
+        project_root    [str]   jvm's workspace also project root dir.
+
+        classpath       [str]   target classpath to compile like `com.hello.Hello`.
+    
+    return: [None]
+    '''
     cwd_tmp = os.getcwd()
     os.chdir(project_root)
     os.system('javac -encoding UTF-8 -d . '+classpath.replace('.', os.path.sep)+'.java')
     os.chdir(cwd_tmp)
 
 def execute_main_class(project_root, classpath):
+    '''
+        Execute compiled main class of project.
+
+    Args:
+        project_root    [str]   jvm's workspace.
+
+        classpath       [str]   main class path like `com.hello.Hello`.
+
+    return: [None]
+    '''
     cwd_tmp = os.getcwd()
     os.chdir(project_root)
     os.system('java '+classpath)
     os.chdir(cwd_tmp)
 
 def get_classpath(project_root, filepath):
+    '''
+        Get standerd classpath from project dir and java file path.
+
+    Args:
+        project_root    [str]   project root dir.
+
+        filepath        [str]   target java file path.
+
+    return: [str]   standerd classpath of java file like `com.hello.Hello`.
+    '''
     class_file = filepath.split(project_root+os.sep)[1]
     class_path = os.path.splitext(class_file)[0].replace(os.path.sep, '.')
     return class_path