[FIXED] Turn dataframe to a dictionary

Issue

I have a dataframe with three columns: pid, idx and value, like this...

I need to convert it to a dictionary where the key is pid and the value is array of tuples(idx, value)

It should look something like this

1 2:0.5 3:0.12 10:0.9 2000:0.3
0 4:1.0 78:0.6 1009:0.2
1 33:0.1 34:0.98 1000:0.8 3300:0.2
1 34:0.1 389:0.32

I'm really stuck on this. Please help

Solution

Iterate on the rows, adding new entry row['pid'] to the dictionary at each iteration.

You can use d.setdefault(k, []).append(v) to avoid a tedious if k in d: d[k].append(v) else: d[k] = [v].

import pandas as pd

df = pd.DataFrame({'pid': [78,78,78,99971,99971,99971], 'idx': [20,164,175,1451,1452,1453], 'value': [0.0,0.0,0.0,0.090909,0.090909,0.090909]})

d = {}
for i, row in df.iterrows():
    d.setdefault(row['pid'], []).append((row['idx'], row['value']))

print(d)
# {78.0: [(20.0, 0.0), (164.0, 0.0), (175.0, 0.0)], 99971.0: [(1451.0, 0.090909), (1452.0, 0.090909), (1453.0, 0.090909)]}

Answered By - Stef