相关疑难解决方法(0)

我想了解嵌套列表理解.下面,我列出了一个列表推导表达式和它们的for循环等价物.
我想知道我的理解是否正确.

例如,

[(min([row[i] for row in rows]),max([row[i] for row in rows])) 
for i in range(len(rows[0]))]

相当于

result=[]
for i in range(len(rows[0])):
  innerResult=[]
  for row in rows:
    innerResult.append(row[i])
  innerResult2=[]
  for row in rows:
    innerResult2.append(row[i])
  tuple=(min(innerResult), max(innerResult2))
  result.append(tuple)

如果我可以概括,我想

[exp2([exp1 for x in xSet]) for y in ySet]

表格可以翻译成以下内容.(我希望我对此是正确的)

result=[]
for y in ySet:
  innerResult =[]
  for x in xSet:
    innerResult.append(exp1)
  exp2Result = exp2(innerResult)
  result.append(exp2Result)

对于更简单的情况,

[exp1 for x in xSet for y in ySet] 

等于

result=[] 
for x in xSet: …