Some tips when you are new to python
Short Explanation
- Python is an interpreted language. This means for you: edit a python source file (eg mappingscript, grammar), save it and run again. No compilation, no linking.
- Python source files always have extension '.py'.
- If you see a '.pyc' file: that is an intermediate file. OK, python does some compilation automatically. Never mind, it is not important. Some systems have '.pyo' files instead. Again, not important.
- Python does not use curly braces ('{...}') or 'BEGIN...END' for functions, loops etc. Python uses 'indentation' instead. Some people love it, some hate it. For me: this is what I always did with all programming languages; now everybody uses the same layout ;-))
- Links to more learning about python are in the page with external links
Tips
- Use a good text editor. This is VERY important. It saves you a lot of time. See in tools page. Three main reasons:
- a good editor has a feature called 'syntax highlighting'. This makes it is lot easier to work with eg mapping scripts.
- a good editor can do a python syntax check on the python source file (a check if it is valid python). This will point you directly to any errors you made.
- make the editor use spaces instead of tabs. This is an important feature when working with python. Never mix tabs and spaces.
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Creating grammars and mapping scripts does not require an "in depth" knowledge of Python, but you need to at least understand general principles of:
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Start with a plugin or example
- most grammars are "similar" (csv, fixed are simple; edifact, x12 are more complex)
- most mappings are "similar" (same functions are used, only "mpaths" change)
- find something close to what you need, see how it works, adapt it.
Installing extra libraries/dependencies
- For linux lots of information about installing libraries is here. Think this is also useful for windows.
- A advanced method is using virtualenv
Feedback
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