import pandas as pd
from functools import reduce

###### TEST BENJI

t = [
    {"word": "a", "pos": 1},

    {"word": "b", "pos": 1},

    {"word": "c", "pos": 1},
    {"word": "c", "pos": 1},
    {"word": "c", "pos": 1},
    {"word": "c", "pos": 4},
    {"word": "c", "pos": 1},
    {"word": "c", "pos": 1},

    {"word": "c", "pos": 2}

]

df = pd.DataFrame(t)

k = df.groupby(by="word")['pos'].apply(list)
result_word = []
result_pos = []

for key, v in k.items():
    result_word.append(key)
    result_pos.append(reduce(lambda a, b : a | b, v))

result = pd.DataFrame({"word" : result_word, "pos" : result_pos})

print(result)