Object-Oriented Collection Wrappers in Python

from flist import flist, fmap

Start with a regular old list:

l = flist([1,2,3,4,5,6,7,8,9,10])

We can filter it:

l.filter(lambda x: x % 3 == 0)   == [3, 6, 9]

Chain more stuff:

(l
  .filter(lambda x: x % 3 == 0)  #  [3,   6,   9]
  .map(lambda x: x + 200)        #  [203, 206, 209]
  .size())                       == 3

See flisttest.py for more examples.

l = flist([1, 2])
l.filter(lambda x: x % 2 == 0).size()      == 1
l.map(lambda x: x + 2)                     == [3, 4]

l = flist([[1, 2], [3, 4]])
l.flatten()                                == [1, 2, 3, 4]

flist([1,2]).flatmap(lambda x: [x, x])          == [1, 1, 2, 2]
flist([1,2]).reduce(lambda a, b: a + b, 0)      == 3
flist(['a','b']).reduce(lambda a, b: a + b, '') == "ab"

m = fmap({'k2': 'v2', 'k1': 'v1'})
sorted(m.keys())                           == ["k1", "k2"]
sorted(m.values())                         == ["v1", "v2"]
sorted(m.items())                          == [["k1", "v1"], ["k2", "v2"]]
sorted(m.map(lambda key, val: key + val))  == ["k1v1", "k2v2"]

list -> map() -> [(key,val)] -> tomap():
m.map(lambda key, val: (key, val)).tomap() == {"k2": "v2", "k1": "v1"}

An flist should transform map entries to fmaps:
l = flist([{'id': 1, 'op': 'registration'}, {'id': 2, 'op': 'transfer'}])
str(type(l[0]))                            == "<class 'flist.fmap'>"
l.map(lambda e: sorted(e.map(lambda key, val: '%s=%s'%(key,val))))
 == [["id=1", "op=registration"], ["id=2", "op=transfer"]]

pluck:
l.map(lambda x: {'id':x['id'], 'optype':x['op']})
 == [{"optype": "registration", "id": 1}, {"optype": "transfer", "id": 2}]