Example 2 inline python

code ... end-code

peforth like eforth attempts to use very basic words to build the entire forth system. Actually, peforth is started with only two words 'code' and 'end-code'.

To define a code word, we press Ctrl-D to make the Windows DOS box environment to accept multiple lines at once then type in the example and at the end drop another Ctrl-D to terminate the multiple-line input.

OK ^D
code hello
    print('hello world!\n')
end-code
^D
OK hello
hello world!

OK see hello
{
    "__class__": "Word",
    "__module__": "peforth.projectk",
    "name": "hello",
    "xt": {
        "__class__": "function",
        "__module__": "peforth.projectk",
        "name": "hello"
    },
    "immediate": false,
    "help": "",
    "comment": "",
    "vid": "forth",
    "wid": 243,
    "type": "code"
}
------------ Source code ------------
def xt(_me=None): ### hello ###
    print('hello world!\n')

-------------------------------------
OK

Where _me refers to the forth word object itself if you need to access its own attributes.

inline python code <py> </py> </pyV> py: py>

python code can be put inline mixed with forth code. This example brings you the python help() utility:

OK py: help()

Welcome to Python 3.6's help utility!

If this is your first time using Python, you should definitely check out
the tutorial on the Internet at http://docs.python.org/3.6/tutorial/.

Enter the name of any module, keyword, or topic to get help on writing
Python programs and using Python modules.  To quit this help utility and
return to the interpreter, just type "quit".

To get a list of available modules, keywords, symbols, or topics, type
"modules", "keywords", "symbols", or "topics".  Each module also comes
with a one-line summary of what it does; to list the modules whose name
or summary contain a given string such as "spam", type "modules spam".

help> quit

You are now leaving help and returning to the Python interpreter.
If you want to ask for help on a particular object directly from the
interpreter, you can type "help(object)".  Executing "help('string')"
has the same effect as typing a particular string at the help> prompt.
OK

This example defines a 'dos-dir' command to go out to DOS box, run the 'dir' DOS command, and come back.

OK : dos-dir <py> import os; os.system('dir') </py> ;
OK dos-dir
 Volume in drive C is Windows
 Volume Serial Number is 2EA4-3202

 Directory of c:\Users\hcche\Documents\GitHub\ML\machine-learning-recipes\src\part_5

2017-09-03  16:09    <DIR>          .
2017-09-03  16:09    <DIR>          ..
2017-06-11  08:53               240 check.py
2017-06-23  17:00    <DIR>          Datasets
2017-06-11  08:53             2,218 Fisher.csv
2017-09-03  17:41             6,912 kNNClassifier.f
2017-09-01  19:45             2,256 kNNClassifier.py
2017-06-11  08:53             2,079 Part5.py
2017-09-03  16:09    <DIR>          __pycache__
               5 File(s)         13,705 bytes
               4 Dir(s)  262,004,789,248 bytes free
OK

Again, use 'see' to view its source code:

OK see dos-dir
{
    "__class__": "Word",
    "__module__": "peforth.projectk",
    "name": "dos-dir",
    "xt": {
        "__class__": "function",
        "__module__": "peforth.projectk"
    },
    "immediate": false,
    "help": "",
    "comment": "",
    "vid": "forth",
    "wid": 242,
    "type": "colon",
    "private": false,
    "cfa": 717
}
------------ Definition in dictionary ------------
00717: def compyle_anonymous():
    import os; os.system('dir') (<class 'function'>)
  2           0 LOAD_CONST               1 (0)
              2 LOAD_CONST               0 (None)
              4 IMPORT_NAME              0 (os)
              6 STORE_FAST               0 (os)
              8 LOAD_FAST                0 (os)
             10 LOAD_ATTR                1 (system)
             12 LOAD_CONST               2 ('dir')
             14 CALL_FUNCTION            1
             16 POP_TOP
             18 LOAD_CONST               0 (None)
             20 RETURN_VALUE
00718: RET  (<class 'NoneType'>)
------------ End of the difinition ---------------
OK

Now we have seen <py> ... </py> brings in a block of python code that does not return value. While <py> ... </pyV> is to envelope a python statement that returns a value back to forth's top of the data stack. We'll use it's short form py> that followed with a statement without space to get CPU information from DOS environment variable PROCESSOR_IDENTIFIER:

OK : CPU ( -- string ) // View CPU info
OK   py> os.getenv('PROCESSOR_IDENTIFIER') . cr ;
OK CPU
Intel64 Family 6 Model 142 Stepping 9, GenuineIntel  
OK

So py> and py: are short form of <py>...</pyV> and <py>...</py> respectively.