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我不确定如何使用循环到返回表格中与 python 独特的条目编号的回路?
原标题:I am not sure how to use for loops to returns number of entries in table that are unique with python?
  • 时间:2012-05-24 21:38:18
  •  标签:
  • python

示例:

help([[1, 2, 2], [1, 1, 2]])

返回 2。

def help(num):
    lst = ()
    for n in num:  
        return(len(lst))

所以我需要桌上所有数字的总和

另一个例子:

help([[32, 12, 52, 63], [32, 64, 67, 52], [64, 64, 17, 34], [34, 17, 76, 32]]) 

返回: 9

问题回答
def allElementsInTable(table):
    for row in table:
        for elem in row:
            yield elem

演示 :

>>> set(allElementsInTable([[1,2,2],[1,1,2]]))
{1,2}

>>> len(set(allElementsInTable([[1,2,2],[1,1,2]])))
2

如果您做了很多表格操作操作, 您可能想要查看 < code> numpy 数组 。

试试这个 (< a href=>"http://docs.python.org/library/itertools.html#itertools. lex" rel="nofollow">itertools. 链 用于“ contailate” the exterables):

table = [ [32, 12, 52, 63], 
          [32, 64, 67, 52], 
          [64, 64, 17, 34], 
          [34, 17, 76, 32] ]

from itertools import chain
n_unique_values = len(set( chain(*table) ))

print n_unique_values # prints 9
>>> x = [[1, 2, 2], [1, 1, 2]]
>>> unique_items = lambda n: len(set(n))
>>> map(unique_items, x)
[2, 2]

@garnertb当然是正确的,

>>> x = [[1, 2, 2], [1, 1, 2]]
>>> map(len, map(set, x))
[2, 2]

问题在于如果x变长,

>>> import itertools
>>> itertools.imap(len, itertools.imap(set, x))
<itertools.imap object at 0xb7437b8c>
compound_list = []
for sublist in lists:
    compound_list += sublist
len(set(compound_list))




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