惯用的方式从每行的列表中打印任意数量的项目

Question

I want to print data from a list, such as:

['0.10', '0.15', '-0.25', '0.30', '1.50', '1.70']

However, rather than printing one element in the list using something like:

for item in list:
    print item

I want to print an arbitrary number of items from the list on each line. I can think of many messy ways to do it and I saw an answer which used the grouper recipe from the itertools page on the docs. I'm happy to use that, but I suspect there might be a better way of doing it.

An example output I might like would be:

0.10   0.15  -0.25
0.30   1.50   1.70

Or:

0.10   0.15  -0.25   0.30
1.50   1.70

So the number of items on each line isn't necessarily a factor of the number of items on the list. Some lines may end with fewer elements if the list is too short.

Answer 1

This works. It seems pretty simple.

for i in range(0, len(some_list), line_length):
    print( some_list[i:i+line_length] )

If you want the literal formatting shown in the question, you'd have to do something like this.

for i in range(0, len(some_list), line_length):
    print( "  ".join( "{0:.2f}".format(x) for x in some_list[i:i+line_length] ) )

Answer 2

Another still (maybe) simpler version:

mylist = ['0.10', '0.15', '-0.25', '0.30', '1.50', '1.70']
line_items = 3

for n, item in enumerate(mylist):
    if (n+1) % line_items:
        print item,
    else:
        print item

produces:

0.10 0.15 -0.25
0.30 1.50 1.70

Answer 3

Think this solution is a little bit more clear:

a = ['0.10', '0.15', '-0.25', '0.30', '1.50', '1.70']
body = []
length = 2
for b in xrange(len(a)):
    body.append(str(a[b]))
    if b % length:
        body.append("\n")
    else:
        body.append("\t")
print "".join(body)

Hope this one helps :)

PS: And actually a one print only solution might be helpful in lists containing many variables.