Python: From dictionary to csv with replicating keys by the length of values

Question

I have the following dictionary:

import pandas as pd
dict_item = {'item1': ['bag', 'phone', 'laptop'],'item2': ['sofa', 'TV', 'bed', 'door', 'window'] }

and I would like to transform it to csv, so far I tried:

df = df.append(pd.DataFrame(data={'item_number':dict_item.keys(),'items':dict_item.values()}))
df

but it gives me following:

But I would like to get following:

So, in other words I would like to replicate the first column which is the keys of dictionary by length of corresponding values

P.S. I created the desired output manually.

Thanks, I would appreciate any help

Asked By: Sascha

||

Source

Answer 1

Just using DataFrame constructor then stack

s=pd.DataFrame(list(dict_item.values()),index=dict_item.keys()).stack().reset_index(level=0)
s.columns=['item_number','items']
s
Out[609]: 
  item_number   items
0       item1     bag
1       item1   phone
2       item1  laptop
0       item2    sofa
1       item2      TV
2       item2     bed
3       item2    door
4       item2  window

Answered By: BENY

Answer 2

Use json_normalize + melt

df = pd.io.json.json_normalize(dict_item)

expand(df.melt(), 'value')

where

def expand(df, col):
    d = {c: df[c].values.repeat(df[col].str.len(), axis=0) for c in df.columns}
    d[col] = [i for sub in df[col] for i in sub]
    return pd.DataFrame(d)

Outputs

    variable    value
0   item1       bag
1   item1       phone
2   item1       laptop
3   item2       sofa
4   item2       TV
5   item2       bed
6   item2       door
7   item2       window

Another option, with pd.DataFrame constructor + melt

pd.DataFrame(dict_item.values(), index=dict_item.keys()).T.melt().dropna()

Answered By: rafaelc

Python: From dictionary to csv with replicating keys by the length of values

Question:

Answers: