Unwind example

First of all, amazing work putting this library together, it is super helpful!

I’m trying to create an UNWIND statement passing it a list of items to unwind. My goal is to have something like this:

UNWIND $batch AS row where $batch is a list of dicts => [{…}, {…}, {…}]

Unfortunately I’m not able to set a list as a valid parameter (unhashable type list). This is my attempt:

batch = [dict(city='hamburg', members=300), dict(city='berlin', members=900), dict(city='koln', members=190)]

unwind_q = Pypher()
batch_p = Param(name='batch', value=batch)
unwind_q.unwind(batch_p).alias('row')

Initially it does not crash but it does crash when trying to see the actual cypher query with the following error:

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-156-1bd1789a4c0a> in <module>
      6 unwind_q.unwind(batch_p).alias('row')
      7 
----> 8 cprint(unwind_q)

<ipython-input-67-e7bd6c8eb90e> in cprint(pypher)
     27 
     28 def cprint(pypher):
---> 29     c = str(pypher)
     30     p = pypher.bound_params
     31     print('Cypher:')

/usr/local/lib/python3.7/site-packages/pypher/builder.py in __str__(self)
    323 
    324     def __str__(self):
--> 325         return self.__unicode__()
    326 
    327     def __unicode__(self):

/usr/local/lib/python3.7/site-packages/pypher/builder.py in __unicode__(self)
    353                 suff = ' '
    354 
--> 355             part = '{}{}{}'.format(pre, str(token), suff)
    356             tokens.append(part)
    357 

/usr/local/lib/python3.7/site-packages/pypher/builder.py in __str__(self)
    323 
    324     def __str__(self):
--> 325         return self.__unicode__()
    326 
    327     def __unicode__(self):

/usr/local/lib/python3.7/site-packages/pypher/builder.py in __unicode__(self)
    636                     arg.parent = self.parent
    637                 elif isinstance(arg, Param):
--> 638                     self.bind_param(arg)
    639                     arg = arg.placeholder
    640 

/usr/local/lib/python3.7/site-packages/pypher/builder.py in bind_param(self, value, name)
    294     def bind_param(self, value, name=None):
    295         self.params.pypher = self
--> 296         return self.params.bind_param(value=value, name=name)
    297 
    298     def __getattr__(self, attr):

/usr/local/lib/python3.7/site-packages/pypher/builder.py in bind_param(self, value, name)
    196                     name = k
    197                     break
--> 198         elif bind and value in self._bound_params.keys():
    199             for k, v in self._bound_params.items():
    200                 if k == value:

TypeError: unhashable type: 'list'

Any ideas on how could I pass a list to UNWIND?

[emehrkay]

Nice. I actually wrote a comment on using Raw, but didn’t hit submit. I was wondering if you could just use __.row.City but that would produce \'row.`City`` and I don’t think that would work for you.

Glad it worked out

[quiin]

Thanks for helping me, really appreciate it! Closing this issue