Cobol Copybook JSONifier

CHANGELOG.md

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What is that for?

This package allows to receive data files from mainframe in ebcdic format and parse it into json based on the cobol copybook schema.

The motivator for that was the necessity to transfer and process some data files from Mainframe on cloud in a easy way for cloud systems.

The main idea here is to convert files from Mainframe that was generated by cobol programs using copybooks into json's registry format.

Cobol copybooks are like data schemas for raw positional files.

To use the package you need:

1. Extract a cobol copybook structure to generate a python dictionary. This dictionary contains objects neededs to build the parser.

2. Build a Parser based on the previous copybook's struture extracted.The parser contains python objects that will handle each kind of data field in the Mainframe's file. That file could be eater EBCDI or ASCII.

   Note:
   Types such as: Binary (BINARY, COMP), COMP3, Numeric Signed ( S9(n) ) are supported in EBCDIC type and needs to be transfer in binary mode from Mainframe.
   ASCII mode suports formats like PIC 9(n), PIC X(n) and Masked PIC +99999.99. These formats can be converted from EBCDIC to ASCII when transfered by FTP, Connect Dirct or other tools from mainframe to cloud or another platform.

These data lines parsed into json could be used to create events, call rest apis and what else you can imagine.

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Straight to the point

Take a look at that package on pypi.org

Installing the pagacke.

pip install coboljsonifier

Using the package.

import simplejson
from coboljsonifier.copybookextractor import CopybookExtractor
from coboljsonifier.parser import Parser
from coboljsonifier.config.parser_type_enum import ParseType

...

# Extracting copybook structure
dict_structure = CopybookExtractor(bookfname).dict_book_structure

# Building a Parser
parser = Parser(dict_structure, ParseType.BINARY_EBCDIC).build()

...

# Parsing the data
parser.parse(data)

# Getting the result (it is an dict type)
dictvalue = parser.value

# Showing the result as Json
print(simplejson.dumps(dictvalue))

The result will be like that:

{"DATA1-REGISTRY-TYPE": 2, "DATA1-COMPANY": 4, "DATA1-USER-ACCOUNT": "0040000000090001111", "DATA1-BIRTH-DATE": "1971-01-21", "DATA1-NAME": "JOHN ROBERT PERIN", "DATA1-CREDIT-LIMIT": 1001, "DATA1-LIMIT-USED": -1000.10, "DATA1-STATUS": [{"DATA1-STATUS-FLAG": "1"}, {"DATA1-STATUS-FLAG": "2"}, {"DATA1-STATUS-FLAG": "3"}, {"DATA1-STATUS-FLAG": "4"}], "FILLER-1": null}

Take a Look at Examples

Use the script examples/prepare_test.py to generate files that will be used by test scripts.

Files generated:

• EBCDIC_BOOK.cob & EBCDIC_DATA.bin
• ASCII_BOOK.cob & ASCII_DATA.bin

After that you can use scripts examples/ascii_parser_test.py and examples/ebcdid_parser_test.py to see how the coboljsonifier package works.

More details in examples/README.md.

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Pre-requisites

• To save in json formats is necessary to use simplejson package. It's to keep compatibility of Decimal pakage that is used to handle monetary values.

• The common json library has incompatibility with Decimal values

• Install simplejson just running pip install simplejson.

• Use simplejson the same way of json.

  Ex.
  install simplejson as json
  It will keep compatibility with the main functionalities.

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Local environment

$ python -m venv venv
$ source venv/bin/activate
$ pip install -r requirements.txt

Testing

Unit Tests:

# Note: Run the tests from main folter of the project
# Ex.: cd cobol-copybook.jsonifier/

# Running only the unittest
$ python -m unittest discover

# Checking test coveraging
$ coverage run -m unittest discover
$ coverage report -m
$ coverage html

Appendix

Table of types treated by CobolJsonifier

    =======================================================================================
      TYPES                             CLASSES                          EBCDIC  ASCII     
    =======================================================================================
      -[Empty]--------------------------------------------------------------------------   
      1)   Empty Content                 Fieldempty                        yes     yes      
      -[Numeric Types without signal]---------------------------------------------------   
      2)   9                             FieldSimpleNumeric                yes     yes      
      3)   9V99                          FieldSimpleNumericDecimals1       yes     yes      
      4)   9V9(2)                        FieldSimpleNumericDecimals2       yes     yes      
      5)   9(12)                         FieldSimpleNumeric1               yes     yes      
      6)   9(12)V99                      FieldSimpleNumeric1Decimals1      yes     yes      
      7)   9(12)V9(2)                    FieldSimpleNumeric1Decimals2      yes     yes      
      -[Numeric Types with signal]------------------------------------------------------   
      8)   S9(12)       [BINARY/COMP3]   FieldSignalNumeric1               yes     no       
      9)   S9(12)V99    [BINARY/COMP3]   FieldSignalNumeric1Decimals1      yes     no       
      10)  S9(12)V9(2)  [BINARY/COMP3]   FieldSignalNumeric1Decimals2      yes     no       
      10)  S9(12)V      [BINARY/COMP3]   FieldSignalNumeric1Decimals3      yes     no
      -[Masked Numeric Types]-----------------------------------------------------------   
      A01) +99999999999999.99            FieldNumericMasked1               no      yes      
           -99999999999999.99                                                               
           +99999999999999                                                                  
           +ZZZZZZZZZZZZZ9.99                                                               
           -ZZZZZZZZZZZZZ9.99        (Note: These are just                                  
            ZZZZZZZZZZZZZZ.ZZ                       some examples)                          
            99999999999999999                                                               
      -[Alphabetic]---------------------------------------------------------------------   
      A02) A(12)                         FieldAlphabetic                   yes     yes      
      -[Alphanumeric]-------------------------------------------------------------------   
      A03) X(12)                         FieldAlphanumeric                 yes     yes      
      -[Undefined]----------------------------------------------------------------------   
      11)  None of the above             FieldUndefined                    yes     yes 
>>>>>>> 7aefd72956e3c26456327dcd222723a04a115bf3
    =======================================================================================

References

• Python Packaging Projects

• Where to put tests

• Python Modules

• Absolute vs Relative python imports

• Python UnitTest