轉換列表中列出的元素

Question

的

可能重複：
Convert list of tuples to list?

我有這樣

[('Knightriders',), ('The Black Knight',), ('Fly by Knight',), ('An Arabian Knight',), ('A Bold, Bad Knight',)...] 

我想這個轉換到一個列表：

['Knightriders', 'The Black Knight', 'Fly by Knight', 'An Arabian Knight', 'A Bold, Bad Knight',...] 

完成此操作最省時的方法是什麼？

Answer 1

最簡單的一種是使用列表理解：

In [126]: lis=[('Knightriders',), ('The Black Knight',), ('Fly by Knight',), ('An Arabian Knight',), ('A Bold, Bad Knight',)] 

In [127]: [x[0] for x in lis] 
Out[127]: 
['Knightriders', 
'The Black Knight', 
'Fly by Knight', 
'An Arabian Knight', 
'A Bold, Bad Knight'] 

或使用itemgetter：

In [128]: from operator import itemgetter 

In [129]: list(map(itemgetter(0),lis)) 
Out[129]: 
['Knightriders', 
'The Black Knight', 
'Fly by Knight', 
'An Arabian Knight', 
'A Bold, Bad Knight'] 

或：

In [131]: [next(x) for x in map(iter,lis)] 
Out[131]: 
['Knightriders', 
'The Black Knight', 
'Fly by Knight', 
'An Arabian Knight', 
'A Bold, Bad Knight'] 

，或者使用通過zip()作爲@DSM提示：

In [132]: zip(*lis)[0] 
Out[132]: 
('Knightriders', 
'The Black Knight', 
'Fly by Knight', 
'An Arabian Knight', 
'A Bold, Bad Knight') 

或使用ast.literal_eval（至少推薦的解決方案或可從來沒有嘗試這個）：

In [148]: from ast import literal_eval 

In [149]: literal_eval(repr(lis).replace(",)",")")) 
Out[149]: 
['Knightriders', 
'The Black Knight', 
'Fly by Knight', 
'An Arabian Knight', 
'A Bold, Bad Knight']