method chains.

Method chains are an amazing programming pattern if you're building an API that needs to be expressive in how it changes data. In this series of video's we will make a pandas-like datacontainer for lists of dictionaries.

Introduction Keep Chains Args Head Select Mutate Sort Bliss

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Notes

This is the class that we have now.

class Clumper:
    def __init__(self, blob):
        self.blob = blob 

    def keep(self, *funcs):
        data = self.blob 
        for func in funcs:
            data = [d for d in data if func(d)]
        return Clumper(data)

    def head(self, n):
        return Clumper([self.blob[i] for i in range(n)])

    def tail(self, n):
        return Clumper([self.blob[-i] for i in range(1, n+1)])

We can now perform commands like;

(Clumper(poke_dict)
  .keep(lambda d: 'Grass' in d['type'],
        lambda d: d['hp'] < 60)
  .head(10)
  .blob)

And;

(Clumper(poke_dict)
  .keep(lambda d: 'Grass' in d['type'],
        lambda d: d['hp'] < 60)
  .tail(10)
  .blob)

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