合并两个列表中独特的方式在Python

Question

我工作的项目欧拉问题5和现在用的是以下几点：

def findLCM(k): 
start=time.time() 
primes=[2,3,5,7,11,13,17,19,23] 
factors=[] 
for factor in range(2,k): 
    if factor in primes: 
     factors.append(factor) 
    else: 
     factorization=[] 
     while factor!=1: 
      for prime in primes: 
       lastFactor=prime 
       if factor%prime==0: 
        factor/=prime 
        factorization.append(lastFactor) 
        break 
     tmpFactors=[] 
     for tmpFactor in factorization: 
      if tmpFactor not in factors: 
       factors.append(tmpFactor) 
      else: 
       tmpFactors.append(tmpFactor) 
       factors.remove(tmpFactor) 
     for tmpFactor in tmpFactors: 
      factors.append(tmpFactor) 
     print factors 
product=1 
for factor in factors: 
    product*=factor 
factors.sort() 
end=time.time() 
fnTime=end-start 
return product, fnTime, factors 

有没有用，我可以组合分解和因素，这样的功能做了Python的功能？例如，如果factors=[2, 3, 5]和factorization=[2, 2, 3]，组合列表应该是[2, 2, 3, 5]。

Answer 1

术语是“multisets的联合”。

它使用collections.Counter用Python实现：

>>> from collections import Counter 
>>> combined = Counter([2, 3, 5]) | Counter([2, 2, 3]) 
>>> list(combined.elements()) 
[2, 2, 3, 5]