Can i integrate multiple lists in python?

Question

Possible Duplicate:
how can I iterate through two lists in parallel in Python?

i have 3 lists like this:

name = ['sam', 'john', 'napoleon', 'tanaka', 'ming']
country = ['USA', 'England', 'France', 'Japan', 'China']
age = [23, 41, 19, 16, 55]

and i want an output like:

sam; USA; 23
john; England; 41
napoleon; France; 19
tanaka; Japan; 16
ming; China; 55

any help would be great. thanks in advance

score 10 · Accepted Answer · answered Jul 12 '12 at 16:21

10

you can use zip():

name = ['sam', 'john', 'napoleon', 'tanaka', 'ming']
country = ['USA', 'England', 'France', 'Japan', 'China']
age = [23, 41, 19, 16, 55]
for x,y,z in zip(name,country,age):
    print("{0}; {1}; {2}".format(x,y,z))

or use map():

mapp=map(lambda x,y,z:"; ".join((x,y,str(z))),name,country,age)
for x in mapp:
    print(x)

output:

sam; USA; 23
john; England; 41
napoleon; France; 19
tanaka; Japan; 16
ming; China; 55

answered Jul 12 '12 at 16:21

Ashwini Chaudhary

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I had an answer, but this one is better. Thanks for the tip on zip! – ChipJust Jul 12 '12 at 16:26
Possibly neater: `map("; ".join, names, countries, map(str, ages))` – Katriel Jul 12 '12 at 16:41

score 3 · Answer 2 · answered Jul 12 '12 at 16:25

3

name = "sam john napoleon tanaka ming".split()
country = "USA England France Japan China".split()
age = [23, 41, 19, 16, 55]

print "\n".join(["%s; %s %d" % (x) for x in zip(name,country,age)])

answered Jul 12 '12 at 16:25

Maria Zverina

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+1 for one liner, use `format()` instead of these old `%s` formatting. – Ashwini Chaudhary Jul 12 '12 at 16:29
1

@AshwiniChaudhary actually `%s` is still totally credable – Jakob Bowyer Jul 12 '12 at 16:30
@JakobBowyer but it's good to use `format()` as the old style formatting might get deprecated. – Ashwini Chaudhary Jul 12 '12 at 16:33
@AshwiniChaudhary might is a big thing in language design – Jakob Bowyer Jul 12 '12 at 19:17
@JakobBowyer PEP 3101: Advanced String Formatting. Note: the 2.6 description `mentions the format() method for both 8-bit and Unicode strings. In 3.0, only the str type (text strings with Unicode support) supports this method; the bytes type does not. The plan is to eventually make this the only API for string formatting, and to start deprecating the % operator in Python 3.1.` source :[What’s New In Python 3.0](http://docs.python.org/release/3.0.1/whatsnew/3.0.html), so it's better if we suggest using `format`. – Ashwini Chaudhary Jul 12 '12 at 19:23
Its still gonna be around for a long long time – Jakob Bowyer Jul 12 '12 at 19:31

TakeS · Answer 3 · 2012-07-12T18:09:50.113

1

Assuming the lists are the same length:

for i in range(len(name)):
    print '%s; %s; %s' %(name[i], country[i], age[i])

UPDATE: This assumes you're using Python 3.x. For 2.x, use xrange for general performance improvement. Alternatively:

for i in range(len(name)):
    print '{0}; {1}; {2}'.format{name[i], country[i], age[i]}

edited Jul 12 '12 at 18:09

answered Jul 12 '12 at 16:24

TakeS

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`range(len(name))` is expensive. – Jakob Bowyer Jul 12 '12 at 16:29
@jakob: do you have to pay for it? <:P – Don Question Jul 12 '12 at 16:33
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@DSeita use `xrange()` on python 2.x and `range()` on python 3.x and use `format()` for formatting strings instead of old style(`%s`) formatting. – Ashwini Chaudhary Jul 12 '12 at 16:34
`range(len(name))` is still a bad idea!, just do `for pos, i in enumerate(name)` – Jakob Bowyer Jul 12 '12 at 19:17

score 0 · Answer 4 · edited Jul 12 '12 at 22:46

0

If you know they will all have the same length, then you can do:

name = ['sam', 'john', 'napoleon', 'tanaka', 'ming']
country = ['USA', 'England', 'France', 'Japan', 'China']
age = [23, 41, 19, 16, 55]

i = 0

for n in name:
    print name[i] + '; ' + country[i] + '; ' + str(age[i])
    i++

edited Jul 12 '12 at 22:46

sth

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answered Jul 12 '12 at 16:27

EnriqueC91

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better use `xrange(len(name))` instead of manually increasing `i`. – Ashwini Chaudhary Jul 12 '12 at 16:28
very true, I think D Seitas answer is my favorite way – EnriqueC91 Jul 12 '12 at 16:30
1

... or use `for i, n in enumerate(name): ...` – glglgl Jul 12 '12 at 16:47
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i++ ? python 2.x doesnt have a ++ operator – Don Question Jul 12 '12 at 18:26

Don Question · Answer 5 · 2012-07-12T18:21:11.317

0

My 2 cents ;-)

Using a generator from the itertools module:

from itertools import izip

nlist = ['%s; %s; %s' %t for t in izip(name, country, age)]

edited Jul 12 '12 at 18:21

answered Jul 12 '12 at 16:30

Don Question

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two problems - missing closing square bracket ... and you can't join an int to a string :) – Maria Zverina Jul 12 '12 at 17:25
so true - you should always try to run your own code ;-) – Don Question Jul 12 '12 at 18:22

Can i integrate multiple lists in python?

5 Answers5