how to use list name from string variable

Question

I am generating these 2 lists using list comprehension.

lists = ['month_list', 'year_list']
for values in lists:
    print [<list comprehension computation>]

>>> ['2012', '2011', '2010', '2009', '2008', '2007', '2006', '2005', '2004', '2003']
>>> ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']

I want to append these 2 dynamically generated lists to this list names.
for example :

month_list = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']  
year_list = ['2012', '2011', '2010', '2009', '2008', '2007', '2006', '2005', '2004', '2003']

Using dynamic variable names is a huge mess. Don't do it. Ever. You are not using not PHP. Simply put those lists in a dict instead of using separate variables for them. — ThiefMaster
– ThiefMaster, Commented May 9, 2012 at 5:37
What does <list comprehension computation> look like? Because the best answer will depend on it. (It most likely won't contain a loop, though.) — Jasmijn
– Jasmijn, Commented May 9, 2012 at 7:24

Ignacio Vazquez-Abrams · Accepted Answer · 2012-05-09 05:35:50Z

3

Sounds to me like you should be using references instead of names.

lists = [month_list, year_list]

But list comprehensions can only create a single list regardless, so you'll need to rethink your problem.

answered May 9, 2012 at 5:35

Ignacio Vazquez-Abrams

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self · Accepted Answer · 2012-05-09 08:15:14Z

2

month_list = []
year_list = []
lists = [month_list, year_list]
dict = {0 : year_list, 1:month_list}

for i, values in enumerate(data[:2]):
    dict[i].append(<data>)

print 'month_list - ', month_list[0]
print 'year_list - ', year_list[0]

>>> month_list -  ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December']
>>> year_list -  ['2012', '2011', '2010', '2009', '2008', '2007', '2006', '2005', '2004', '2003']

edited May 9, 2012 at 8:15

answered May 9, 2012 at 7:04

self

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1 Comment

Jasmijn Over a year ago

Why string keys? Why not integer keys?

Gergely Sipkai · Accepted Answer · 2012-05-09 11:22:44Z

2

You can add global variables to the modul's namespace and connect values to them with this method:

globals()["month_list"] = [<list comprehension computation>]

Read more about namespaces in Python documents.

Or you can store these list in a new dictionary.

your_dictionary = {}
your_dictionary["month_list"] = [<list comprehension computation>]

edited May 9, 2012 at 11:22

answered May 9, 2012 at 10:43

Gergely Sipkai

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Comments

Amber · Accepted Answer · 2012-05-09 05:35:00Z

1

Why use strings in the first place?

Why not just do...

lists = [month_list, year_list]
for list_items in lists:
    print repr(list_items)

after you define the two lists?

answered May 9, 2012 at 5:35

Amber

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