CODEWITHSUNDEEP
pythonpython-3.x
user3431083
user3431083

Reputation: 414

Pythonic way of loading a list from a SQL table structure, python 3.x

I imported a SQL table into a python list of lists and I would like to convert the format, in a kind of transpose manner, into a different format, where the key 'column' from the input table determines which elements are grouped in the output col. see example:

input list:

[
    (1, 'eq510240'),
    (1, 'eq510245'),
    (1, 'eq510246'),
    (2, 'eq510252'),
    (2, 'eq510291'),
    (3, 'eq510298')
]

desired output list:

[
    ('eq510240', 'eq510245', 'eq510246'),
    ('eq510252', 'eq510291'),
    ('eq510298')
]

Upvotes: 0

Views: 64

Answers (1)

Cory Kramer
Cory Kramer

Reputation: 117926

You can use itertools.groupby to group the elements by the first value of each tuple. Then in a list comprehension create a tuple from the values in each group.

>>> from itertools import groupby
>>> [tuple(j[1] for j in g[1]) for g in groupby(l, key=lambda i: i[0])]
[('eq510240', 'eq510245', 'eq510246'),
 ('eq510252', 'eq510291'),
 ('eq510298',)]

Upvotes: 3

Related Questions