比如a = [1, 2, 3], b = [4, 5, 6]
合并为[1, 4, 2, 5, 3, 6]
你觉得怎么写比较优雅?
黄舟2017-04-17 14:30:20
python
from itertools import chain list(chain.from_iterable(zip(a, b))) # py2 list(chain(*zip(a, b)))
ringa_lee2017-04-17 14:30:20
Correction: There is a problem with the previous code, update it once.
I don’t know if it’s elegant, but it should save memory:
def xmerge(a, b):
alen, blen = len(a), len(b)
mlen = min(alen, blen)
for i in xrange(mlen):
yield a[i]
yield b[i]
if alen > blen:
for i in xrange(mlen, alen):
yield a[i]
else:
for i in xrange(mlen, blen):
yield b[i]
a = [1, 2, 3]
b = [5, 6, 7, 8, 9, 10]
c = [i for i in xmerge(a, b)]
print c
c = [i for i in xmerge(b, a)]
print c
大家讲道理2017-04-17 14:30:20
It turns out that stackoverflow has already discussed it, and the writing method is very awkward. I personally love this:
The cycle/islice functions called are all from itertools
def roundrobin(*iterables):
"roundrobin('ABC', 'D', 'EF') --> A D E B F C"
# Recipe credited to George Sakkis
pending = len(iterables)
nexts = cycle(iter(it).next for it in iterables)
while pending:
try:
for next in nexts:
yield next()
except StopIteration:
pending -= 1
nexts = cycle(islice(nexts, pending))
怪我咯2017-04-17 14:30:20
python
def xmerge(a, b): tmp = (list(a), list(b)); return [tmp[i%2].pop(0) if tmp[i%2] else tmp[1-i%2].pop(0) for i in xrange(0, len(a) + len(b))] print xmerge([1,2,3], [5,6,7,8,9]) print xmerge([1,2,3,4,5], [7,8,9])
Is this so?
//Halfway through writing, I searched for ternary expressions in python and remembered that I used python to feel like this kind of mythical beast flying by...
//But there is also a language with three elements written as if a then b else c
, which I can still understand now...
巴扎黑2017-04-17 14:30:20
python3.3
result = [list(zip(a, b))[i][j] for i in range(len(a)) for j in range(len(list(zip(a, b))[0]))]
虽然是一行,但是有点牵强,小括号太多
ringa_lee2017-04-17 14:30:20
python
# Python 3 def interpolate(*seqs): for items in zip(*seqs): yield from items >>> list(interpoltae('string', 'asdfgh')) ['s', 'a', 't', 's', 'r', 'd', 'i', 'f', 'n', 'g', 'g', 'h']
There is a question, what should I do if these sequences are not all of equal length. The above solution is based on the smallest length:
python
>>> list(interpolate('string', 'asdf')) ['s', 'a', 't', 's', 'r', 'd', 'i', 'f']
But what if you don’t choose the smallest one? Complementary characters? What characters should be added?
PHP中文网2017-04-17 14:30:20
For elegant data processing, scipy series libraries are still needed.
There is a ready-made flatten function in matplotlib that can be used.
from matplotlib.cbook import flatten
a = [1, 2, 3]
b = [4, 5, 6]
list(flatten(zip(a,b)))
巴扎黑2017-04-17 14:30:20
a = [1, 2, 3]
b = [4, 5, 6]
def slove(a, b):
c = []
i = 0
j = 0
while i<len(a) and j<len(b):
c.append(a[i])
c.append(b[j])
i += 1
j += 1
while i < len(a):
c.append(a[i])
i += 1
while j < len(b):
c.append(b[j])
j += 1
print(c)
if name == 'main':
slove(a, b)
天蓬老师2017-04-17 14:30:20
a=[1,2,3]
b=[4,5,6]
a=set(a)
b=set(b)
c=list(a|b)
If it is just a merge of lists, can it be converted into set() and then the intersection operation
Set is faster than list when doing list merge.
But @lohocla4dam helped point out the shortcomings