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
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))
pythondef 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...
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
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
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:
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
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...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:
But what if you don’t choose the smallest one? Complementary characters? What characters should be added?
For elegant data processing, scipy series libraries are still needed.
There is a ready-made flatten function in matplotlib that can be used.
a = [1, 2, 3]
b = [4, 5, 6]
一般的方法
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
if name == 'main':
slove(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