Python 列表運算式 ，迭代器(1)

標籤：ready   seq   where   keyword   ase   ==   rabl   for迴圈   hand   

python 環境 3.5

1、列表：   s = [];   for i in s:      i = handleFunction(i);      s.append(i)2、列表   s=[handleFunction(i) for i in s]  或者   s=[handleFunction(str(i)) for i in s]    //轉為字串
3、不用for迴圈（for迴圈的替代）map
   map(func, seq1[, seq2,…])   Python 3.0以上返回迭代器，2.7 返回list
   eg: seq 只有只有一個參數時： map==for
      **將元群組轉換成list*** >>> 
       list(map(int,(1,2,3))) [1, 2, 3] 
     ***將字串轉換成list*** >>>list(map(int,‘1234‘)) [1, 2, 3, 4] 
     ***提取字典的key，並將結果存放在一個list中*** >>> res=list(map(int,{"1":"a","2":"b"})) [1, 2] 
     #將小寫轉成大寫 def u_to_l (s): return s.upper() print list(map(u_to_l,‘asdfd‘))

map(function, iterable, ...)

Return an iterator that applies function to every item of iterable, yielding the results. If additional iterable arguments are passed, function must take that many arguments and is applied to the items from all iterables in parallel. With multiple iterables, the iterator stops when the shortest iterable is exhausted. For cases where the function inputs are already arranged into argument tuples, 

 

Python 列表運算式 ，迭代器(1)