Sort list by month order and add the missing month

user_13292088 0
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I've my month_list that I got using most_common() from collection module that looks like this:

[('October', 3744), ('September', 3329), ('November', 3072), ('March', 2630), ('February', 2268), ('June', 2046), ('December', 1959), ('August', 1880), ('May', 1567), ('July', 1289), ('April', 1237), ('January', 1155)]

What I want is index the list with the correct months order, I've tried like this:

month_index  = ['January', 'February',' March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']

month_list.index(month_index)

But I get this error

ValueError: ['January', 'February', ' March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'] is not in list

Also I've another list month_list2 where January is totally missing, but when sorting I'd like to have something like this:

[('January','NA'), ('February', 568), ('March', 3481)...]

is it possible? Thanks!

python
6 Answers

To sort list, you should use sort with index being its key:

month_list.sort(key = lambda item:month_index.index(item[0]))

.. but, you also want to add missing items. So you'd better convert month_list to a dict, and access dict item with NA being its default value:

month_dict = dict(month_list)
month_list = [(month, month_dict.get(month, 'NA')) for month in month_index]
user_15334600

You could do it using the module datetime. The %B represents the months' format.

The following can be achieved as shown below:

from datetime import datetime
months = [('October', 3744), ('September', 3329), ('November', 3072), ('March', 2630), ('February', 2268), ('June', 2046), ('December', 1959), ('August', 1880), ('May', 1567), ('July', 1289), ('April', 1237), ('January', 1155)]
sorted(months, key=lambda m: datetime.strptime(m[0], "%B"))
user_130070410

Here is a solution with inserting missing data

my_months = [
("October", 3744),
("September", 3329),
("November", 3072),
("March", 2630),
("February", 2268),
("June", 2046),
("December", 1959),
("August", 1880),
("May", 1567),
("July", 1289),
("April", 1237),
("January", 1155),
]

month_index = [
    "January",
    "February",
    "March",
    "April",
    "May",
    "June",
    "July",
    "August",
    "September",
    "October",
    "November",
    "December",
]

ordered_months = sorted(my_months, key=lambda v: month_index.index(v[0]))

# checks if all months exist

months_in_ordered_list = [month[0] for month in ordered_months]
for month in month_index:
    if month not in months_in_ordered_list:
        ordered_months.insert(month_index.index(month), (month, 'NA'))
user_116849470

Try:

>>> dct = {'January': 1, 'February': 2, 'March': 3, 'April': 4, 'May': 5, 'June': 6, 'July': 7, 'August': 8, 'September': 9, 'October': 10, 'November': 11, 'December': 12}
>>> lot = [('October', 3744), ('September', 3329), ('November', 3072), ('March', 2630), ('February', 2268), ('June', 2046), ('December', 1959), ('August', 1880), ('May', 1567), ('July', 1289), ('April', 1237)]
>>> sorted([(k, dict(lot).get(k, 'NA')) for k in dct], key=lambda x: dct[x[0]])
[('January', 'NA'), ('February', 2268), ('March', 2630), ('April', 1237), ('May', 1567), ('June', 2046), ('July', 1289), ('August', 1880), ('September', 3329), ('October', 3744), ('November', 3072), ('December', 1959)]
>>>
user_87083640

You cannot pass a list to month_list.index() it accepts only one value as argument.

Moreover your month_list ist a list of tuples and you are trying to index a string in the list.

convert the month_list to a list of only months:

month_list_str = [i[0] for i in month_list]

Output:

month_list_str
Out[25]: 
['October',
 'September',
 'November',
 'March',
 'February',
 'June',
 'December',
 'August',
 'May',
 'July',
 'April',
 'January']

Then you can index and sort this list:

out_list = []
for m in month_index:
    if m in month_list_str:
        i = month_list_str.index(m)
        out_list += [(m,month_list[i][1])]
    else:
        out_list += [(m,'NA')]

Output:

out_list
Out[39]: 
[('January', 1155),
 ('February', 2268),
 (' March', 'NA'),
 ('April', 1237),
 ('May', 1567),
 ('June', 2046),
 ('July', 1289),
 ('August', 1880),
 ('September', 3329),
 ('October', 3744),
 ('November', 3072),
 ('December', 1959)]
user_82304040

If you have a duplicate month and you want sort it. you need to consider the second number in the tuple. I hope my answer help you. (in this example we have two 'January' and two 'February')

month_list = [('January', 3329), ('November', 3072), ('February', 2630), ('February', 2268), ('June', 2046), ('December', 1959), ('August', 1880), ('May', 1567), ('July', 1289), ('April', 1237), ('January', 1155)]
month_index  = ['January', 'February','March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']

month_list = month_list + [(m, 'NA') for m in month_index if m not in dict(month_list)]

sorted(month_list, key=lambda x: (month_index.index(x[0]), x[1]))

Output:

[('January', 1155),
 ('January', 3329),
 ('February', 2268),
 ('February', 2630),
 ('March', 'NA'),
 ('April', 1237),
 ('May', 1567),
 ('June', 2046),
 ('July', 1289),
 ('August', 1880),
 ('September', 'NA'),
 ('October', 'NA'),
 ('November', 3072),
 ('December', 1959)]
user_17405770
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