Membaca data bersarang ke DataFrame

Mengubah Bentuk Data dengan pandas

Maria Eugenia Inzaugarat

Data Scientist

Ulasan

Ubah bentuk DataFrame dan Series
Pecah list dalam kolom
Pisah dan gabung string

Format JSON

JavaScript Object Notation
Format pertukaran data
Mudah dibaca dan ditulis manusia
Mudah diparse dan dibuat mesin

Format JSON

my_writer

{
  "first" : "Mary",
  "last" : "Shelley",
  "country" : "England",
  "books" : 12
}

JSON bersarang

writers

writers = [
            {
              "first": "Mary",
              "last": "Shelley",
              "books": {"title": "Frankenstein", "year": 1818}
            },
            {
              "first": "Ernest",
              "last": "Hemingway",
              "books": {"title": "The Old Man and the Sea", "year": 1951}
            }
          ]

Normalisasi data

from pandas import json_normalize

json_normalize(writers)

    first       last              books.title  books.year
0    Mary    Shelley             Frankenstein        1818
1  Ernest  Hemingway  The Old Man and the Sea        1951

Normalisasi data

writers_norm = json_normalize(writers, sep='_')
writers_norm

    first       last              books_title  books_year
0    Mary    Shelley             Frankenstein        1818
1  Ernest  Hemingway  The Old Man and the Sea        1951

Normalisasi data

pd.wide_to_long(writers_norm, stubnames=['books'], i=['first', 'last'], j='feature', sep='_', suffix='\w+')

                                            books
first  last      feature                         
Mary   Shelley   title               Frankenstein
                 year                        1818
Ernest Hemingway title    The Old Man and the Sea
                 year                        1951

JSON kompleks

writers

[
    {'name': 'Mary',
     'last': 'Shelley',
     'books': [{'title': 'Frankestein', 'year': 1818},
                {'title': 'Mathilda ', 'year': 1819},
                {'title': 'The Last Man', 'year': 1826}]},
    {'name': 'Ernest',
     'last': 'Hemmingway',
     'books': [{'title': 'The Old Man and the Sea', 'year': 1951},
               {'title': 'The Sun Also Rises', 'year': 1927}]}
]

JSON kompleks

json_normalize(writers)

     name        last                                              books
0    Mary     Shelley  [{'title': 'Frankestein', 'year': 1818}, {'tit...
1  Ernest  Hemmingway  [{'title': 'The Old Man and the Sea', 'year': ...

Record path

json_normalize(writers, record_path='books')

                     title  year
0              Frankestein  1818
1                Mathilda   1819
2             The Last Man  1826
3  The Old Man and the Sea  1951
4       The Sun Also Rises  1927

Metadata

json_normalize(writers, record_path='books', meta=['name', 'last'])

                     title  year    name        last
0              Frankestein  1818    Mary     Shelley
1                Mathilda   1819    Mary     Shelley
2             The Last Man  1826    Mary     Shelley
3  The Old Man and the Sea  1951  Ernest  Hemmingway
4       The Sun Also Rises  1927  Ernest  Hemmingway

Ayo berlatih!

Mengubah Bentuk Data dengan pandas