Best import pattern to know you have upsert method ver 3.7.0 +

Phuket2

Sorry for dumb question. But can you plesase advise the best import pattern so i know I have a version that supports upsert method. I have tried various ways, pretty sure they are all bad. Pretty sure upsert is only available from version 3.7.0 onwards.

But not sure the best way to test for this in code concisely.

I did the below, which does not work. I tried different variations also that did not work. More importantly, I would like to know the correct python pattern to do the test.

try:
    from tinydb import TinyDB, __version__ as tinydb_version, upsert as tinydb_upsert
except:
    raise ImportError('Verion 3.7.0 of TinyDB or greater required for this app')

alshapton

Phuket2

This is some code I rigged up which will take a method and tell you if it is supported or not ..... (sorry - not worked out how to reformat this stuff into code yet ? so the indentation isnt quite right.....

db = TinyDB('data.json',storage=JSONStorage)
try:
doesitexist = db.upsert
except AttributeError:
print "Upsert is not supported"
else:
print "Upsert IS supported"

Phuket2

alshapton , thank you for your reply. I really want to be able to do it in the import statement if possible. Basically the test a one liner. Not sure its possible, but i feel it should be.

In terms of posting code here, if the first line you use 3 backticks followed by python, then close the block with 3 back ticks, the code will display correctly.
A pic below

The below should be displayed as the pic.

from tinydb import TinyDB

db = TinyDB('data.json')
try:
    doesitexist = db.upsert3
except AttributeError:
    print("Upsert is not supported")
else:
    print("Upsert IS supported")

msiemens

Phuket2 I really want to be able to do it in the import statement if possible.

Unfortunately it's not impossible to do a version check during import. As alshapton mentioned, you can check if the method exists and catch the AttributeError if it doesn't. Another way would be to parse the version string using something like:

tuple(int(i) for i in tinydb_version.split('.')) >= (3, 7, 0)

I'm assuming you're using TinyDB in a project of yours as a dependency? If so, do you have a requirements.txt or a dependencies list in your setup.py? If not, how do you install depenencies in your application/library?

Cheers!

alshapton

I guess a slight improvement would be to create a function out of the code that I made and parameterise things a little to make it reusable........

Phuket2

Ok, got it! Thanks for both your help. Good to know, I am not missing something silly. My usage is a little different because I mainly code (hobby style) in the iOS Pythonista. While pip is possible, but because of rules etc... for iOS apps, its still a bit of a work around. I am hoping the developer of Pythonista will add TinyDB as part of the shipped modules (batteries included). But as an FYI, TinyDB works very nicely in Pythonista. One limitation we have in Pythonista is that we can only pip install pure python modules ourselves. But of course that limitation does not apply to the modules the developer ships in the APP. So I also asked him to consider to ship ujson if he adds TinyDB to the batteries inc. As it's not possible for us as users to pip install ujson as its a C implementation.

Anyway, thanks again. Just thought I would explain why some of my questions may seem a little strange. My environment is not the same as a desktop.

Phuket2

Just as an fyi, i went for the below as my std test for TinyDB. I decided to stick with versions rather than test for methods. As I say, when I am working on iOS with Pythonista, its a little different.

'''
Import tinydb and make sure we have a version we can work with
'''
from tinydb import TinyDB, where, __version__

minimum_version = (3, 7, 0)
if not tuple(int(i) for i in __version__.split('.')) >= minimum_version:
    msg = '''Your version of TinyDB is out of date for the functionality ''' \
          '''required by this App. Your version is {}.  Version {} is required.'''
    raise ValueError(msg.format(__version__,\
                     str(minimum_version).replace(', ', '.')))