Python list pass-through delete element

Python list traversal time to delete really need to pay attention to, today to help the classmate to deal with data, unexpectedly silly force.

Demand:

In addition to the first column, add an ordinal to each column such as "1:0", "2:0", "3:20,100,307", and then delete the data after the colon as 0.

Recommended Practice:

arrays = [[' 5001 ', ' 0 ', ' 0 ', ' 20100307 ', ' 20150109 ', ' 2 ', ' 3 ', ' 75 ', ' 0 ', ' 0 ', ' 114 ', ' 13 ', ' 2 ', ' 0 ', ' 0 '],[' 10001 ', ' 0 ', ' 2 ', ' 20100318 ', ' 20150119 ', ' 2 ', ' 3 ', ' 58 ', ' 0 ', ' 0 ', ' 1 ', ' 5 ', ' 1 ', ' 0 ', ' 0 '],[' 15001 ', ' 0 ', ' 2 ', ' 20100329 ', ' 20150130 ' , ' 9 ', ' 14 ', ' 70 ', ' 0 ', ' 0 ', ' 1 ', ' 31 ', ' 7 ', ' 11 ', ' 7 '],[' 20001 ', ' 0 ', ' 0 ', ' 20100401 ', ' 20150117 ', ' 3 ', ' 5 ', ' 71 ', ' 1 ', ' 75 ', ' 1 ', ' 1 ', ' 1 ', ' 0 ', ' 0 '],[' 22001 ', ' 0 ', ' 1 ', ' 20100401 ', ' 20150125 ', ' 7 ', ' 11 ', ' 58 ', ' 0 ', ' 0 ', ' 51 ', ' 40 '  , ' 1 '],[' 24001 ', ' 0 ', ' 0 ', ' 20100401 ', ' 20141209 ', ' 1 ', ' 1 ', ' 138 ', ' 0 ', ' 0 ', ' 1 ', ' 1 ', ' 1 ', ' 0 ', ' 0 '],[' 44001 ', ' 20100428 ', ' 20141130 ', ' 1 ', ' 1 ', ' 85 ', ' 0 ', ' 0 ', ' 1 ', ' 0 ', ' 0 ', ' 0 ', ' 0 '],[' 45001 ', ' 1 ', ' 0 ', ' 20100429 ', ' 20141127 ', ' 1 ' ', ' 1 ', ' 128 ', ' 0 ', ' 0 ', ' 1 ', ' 24 ', ' 3 ', ' 0 ', ' 0 '],[' 50001 ', ' 0 ', ' 0 ', ' 20100506 ', ' 20141230 ', ' 1 ', ' 2 ', ' 67 ', ' 0 ', ' 0 ', '  44 ', ' 6 ', ' 1 ', ' 4 ', ' 1 '],[' 69001 ', ' 0 ', ' 0 ', ' 20100524 ', ' 20150129 ', ' 16 ', ' 20 ', ' 90 ', ' 2 ', ' 220 ', ' 236 ', ' 44 ', ' 18 ', ' 3 ', ' 2 '],[' 71001 ', ' 0 ', ' 2 ', ' 20100526 ', ' 20141224 ', ' 9 ', ' + ', ' 0 ', ' 0 ', ' arrays ', ' 4 ', ' 7 ', ' One ', ' Every_list ']]for: #add col num ber for I in range (len (every_list)): if i = = 0:continue Every_list[i] = str (i) + ":" +every_lis T[i] #remove col which value==0 every_list = filter (lambda e:e.split (":") [-1]! = ' 0 ', every_list) print every _list

Results:

[' 5001 ', ' 3:20,100,307 ', ' 4:20,150,109 ', ' 5:2 ', ' 6:3 ', ' 7:75 ', ' 10:114 ', ' 11:13 ', ' 12:2 '] [' 10001 ', ' 2:2 ', ' 3:20,100,318 ', ' 4:20,150,119 ', ' 5:2 ', ' 6:3 ', ' 7:58 ', ' 10:1 ', ' 11:5 ', ' 12:1 '] [' 15001 ', ' 2:2 ', ' 3:20,100,329 ', ' 4:20,150,130 ', ' 5:9 ', ' 6:14 ', ' 7:70 ', ' 10:1 ', ' 11:31 ', ' 12:7 ', ' 13:11 ', ' 14:7 '] [' 20001 ', ' 3:20,100,401 ', ' 4:20,150,117 ', ' 5:3 ', ' 6:5 ', ' 7:71 ', ' 8:1 ', ' 9:75 ', ' 10:1 ', ' 11:1 ', ' 12:1 '] [' 22001 ', ' 2:1 ', ' 3:20,100,401 ', ' 4:20,150,125 ', ' 5:7 ', ' 6:11 ', ' 7:58 ', ' 10:51 ', ' 11:40 ', ' 12:12 ', ' 13:2 ', ' 14:1 '] [' 24001 ', ' 3:20,100,401 ', ' 4:20,141,209 ', ' 5:1 ', ' 6:1 ', ' 7:138 ', ' 10:1 ', ' 11:1 ', ' 12:1 '] [' 44001 ', ' 1:1 ', ' 3:20,100,428 ', ' 4:20,141,130 ', ' 5:1 ', ' 6:1 ', ' 7:85 ', ' 10:1 '] [' 45001 ', ' 1:1 ', ' 3:20,100,429 ', ' 4:20,141,127 ', ' 5:1 ', ' 6:1 ', ' 7:128 ', ' 10:1 ', ' 11:24 ', ' 12:3 '] [' 50001 ', ' 3:20,100,506 ', ' 4:20,141,230 ', ' 5:1 ', ' 6:2 ', ' 7:67 ', ' 10:44 ', ' 11:6 ', ' 12:1 ', ' 13:4 ', ' 14:1 '] [' 69001 ', ' 3:20,100,524 ', ' 4:20,150,129 ', ' 5:16 ', ' 6:20 ', ' 7:90 ', ' 8:2 ', ' 9:220 ', ' 10:236 ', ' 11:44 ', ' 12:18 ', ' 13:3 ', ' 14:2 ' [ ' 71001 ', ' 2:2 ', ' 3:20,100,526 ', ' 4:20141224 ', ' 5:9 ', ' 6:15 ', ' 7:64 ', ' 10:57 ', ' 11:30 ', ' 12:7 ', ' 13:11 ', ' 14:4 '] 

In fact, the beginning of the silly practice:

arrays = [[' 5001 ', ' 0 ', ' 0 ', ' 20100307 ', ' 20150109 ', ' 2 ', ' 3 ', ' 75 ', ' 0 ', ' 0 ', ' 114 ', ' 13 ', ' 2 ', ' 0 ', ' 0 '],[' 10001 ', ' 0 ', ' 2 ', ' 20100318 ', ' 20150119 ', ' 2 ', ' 3 ', ' 58 ', ' 0 ', ' 0 ', ' 1 ', ' 5 ', ' 1 ', ' 0 ', ' 0 '],[' 15001 ', ' 0 ', ' 2 ', ' 20100329 ', ' 20150130 ' , ' 9 ', ' 14 ', ' 70 ', ' 0 ', ' 0 ', ' 1 ', ' 31 ', ' 7 ', ' 11 ', ' 7 '],[' 20001 ', ' 0 ', ' 0 ', ' 20100401 ', ' 20150117 ', ' 3 ', ' 5 ', ' 71 ', ' 1 ', ' 75 ', ' 1 ', ' 1 ', ' 1 ', ' 0 ', ' 0 '],[' 22001 ', ' 0 ', ' 1 ', ' 20100401 ', ' 20150125 ', ' 7 ', ' 11 ', ' 58 ', ' 0 ', ' 0 ', ' 51 ', ' 40 '  , ' 1 '],[' 24001 ', ' 0 ', ' 0 ', ' 20100401 ', ' 20141209 ', ' 1 ', ' 1 ', ' 138 ', ' 0 ', ' 0 ', ' 1 ', ' 1 ', ' 1 ', ' 0 ', ' 0 '],[' 44001 ', ' 20100428 ', ' 20141130 ', ' 1 ', ' 1 ', ' 85 ', ' 0 ', ' 0 ', ' 1 ', ' 0 ', ' 0 ', ' 0 ', ' 0 '],[' 45001 ', ' 1 ', ' 0 ', ' 20100429 ', ' 20141127 ', ' 1 ' ', ' 1 ', ' 128 ', ' 0 ', ' 0 ', ' 1 ', ' 24 ', ' 3 ', ' 0 ', ' 0 '],[' 50001 ', ' 0 ', ' 0 ', ' 20100506 ', ' 20141230 ', ' 1 ', ' 2 ', ' 67 ', ' 0 ', ' 0 ', '  44 ', ' 6 ', ' 1 ', ' 4 ', ' 1 '],[' 69001 ', ' 0 ', ' 0 ', ' 20100524 ', ' 20150129 ', ' 16 ', ' 20 ', ' 90 ', ' 2 ', ' 220 ', ' 236 ', ' 44 ', ' 18 ', ' 3 ', ' 2 '],[' 71001 ', ' 0 ', ' 2 ', ' 20100526 ', ' 20141224 ', ' 9 ', ' + ', ' 0 ', ' 0 ', ' arrays ', ' 4 ', ' 7 ', ' One ', ' Every_list ']]for: #add col num ber for I in range (len (every_list)): if i = = 0:continue Every_list[i] = str (i) + ":" +every_lis T[i] #remove col which value==0 for J in Every_list:if J.split (":") [-1] = = ' 0 ': #if float (j.split (': ') [-1]) = = 0:every_list.remove (j) Print Every_list

The result is wrong:

[' 5001 ', ' 2:0 ', ' 3:20,100,307 ', ' 4:20,150,109 ', ' 5:2 ', ' 6:3 ', ' 7:75 ', ' 9:0 ', ' 10:114 ', ' 11:13 ', ' 12:2 ', ' 14:0 '] [' 10001 ', ' 2:2 ', ' 3:20,100,318 ', ' 4:20,150,119 ', ' 5:2 ', ' 6:3 ', ' 7:58 ', ' 9:0 ', ' 10:1 ', ' 11:5 ', ' 12:1 ', ' 14:0 '] [' 15001 ', ' 2:2 ', ' 3:20,100,329 ', ' 4:20,150,130 ', ' 5:9 ', ' 6:14 ', ' 7:70 ', ' 9:0 ', ' 10:1 ', ' 11:31 ', ' 12:7 ', ' 13:11 ', ' 14:7 '] [' 20001 ', ' 2:0 ', ' 3:20,100,401 ', ' 4:20,150,117 ', ' 5:3 ', ' 6:5 ', ' 7:71 ', ' 8:1 ', ' 9:75 ', ' 10:1 ', ' 11:1 ', ' 12:1 ', ' 14:0 '] [' 22001 ', ' 2:1 ', ' 3:20,100,401 ', ' 4:20,150,125 ', ' 5:7 ', ' 6:11 ', ' 7:58 ', ' 9:0 ', ' 10:51 ', ' 11:40 ', ' 12:12 ', ' 13:2 ', ' 14:1 '] [' 24001 ', ' 2:0 ', ' 3:20,100,401 ', ' 4:20,141,209 ', ' 5:1 ', ' 6:1 ', ' 7:138 ', ' 9:0 ', ' 10:1 ', ' 11:1 ', ' 12:1 ', ' 14:0 '] [' 44001 ', ' 1:1 ', ' 3:20,100,428 ', ' 4:20,141,130 ', ' 5:1 ', ' 6:1 ', ' 7:85 ', ' 9:0 ', ' 10:1 ', ' 12:0 ', ' 14:0 '] [' 45001 ', ' 1:1 ', ' 3:20,100,429 ', ' 4:20,141,127 ', ' 5:1 ', ' 6:1 ', ' 7:128 ', ' 9:0 ', ' 10:1 ', ' 11:24 ', ' 12:3 ', ' 14:0 '] [' 50001 ', ' 2:0 ', ' 3:20,100,506 ', ' 4:20,141,230 ', ' 5:1 ', ' 6:2 ', ' 7:67 ', ' 9:0 ', ' 10:44 ', ' 11:6 ', ' 12:1 ', ' 13:4 ', ' 14:1 '] [' 69001 ', ' 2:0 ', '3:20,100,524 ', ' 4:20,150,129 ', ' 5:16 ', ' 6:20 ', ' 7:90 ', ' 8:2 ', ' 9:220 ', ' 10:236 ', ' 11:44 ', ' 12:18 ', ' 13:3 ', ' 14:2 ' [' 71001 ', ' 2 : 2 ', ' 3:20,100,526 ', ' 4:20,141,224 ', ' 5:9 ', ' 6:15 ', ' 7:64 ', ' 9:0 ', ' 10:57 ', ' 11:30 ', ' 12:7 ', ' 13:11 ', ' 14:4 ']

Analysis:

Because the Python list removes the element, it's not good.

This is a bad reason:

Delete is not clean.


Later genius, the list into list[:]:

arrays = [[' 5001 ', ' 0 ', ' 0 ', ' 20100307 ', ' 20150109 ', ' 2 ', ' 3 ', ' 75 ', ' 0 ', ' 0 ', ' 114 ', ' 13 ', ' 2 ', ' 0 ', ' 0 '],[' 10001 ', ' 0 ', ' 2 ', ' 20100318 ', ' 20150119 ', ' 2 ', ' 3 ', ' 58 ', ' 0 ', ' 0 ', ' 1 ', ' 5 ', ' 1 ', ' 0 ', ' 0 '],[' 15001 ', ' 0 ', ' 2 ', ' 20100329 ', ' 20150130 ' , ' 9 ', ' 14 ', ' 70 ', ' 0 ', ' 0 ', ' 1 ', ' 31 ', ' 7 ', ' 11 ', ' 7 '],[' 20001 ', ' 0 ', ' 0 ', ' 20100401 ', ' 20150117 ', ' 3 ', ' 5 ', ' 71 ', ' 1 ', ' 75 ', ' 1 ', ' 1 ', ' 1 ', ' 0 ', ' 0 '],[' 22001 ', ' 0 ', ' 1 ', ' 20100401 ', ' 20150125 ', ' 7 ', ' 11 ', ' 58 ', ' 0 ', ' 0 ', ' 51 ', ' 40 '  , ' 1 '],[' 24001 ', ' 0 ', ' 0 ', ' 20100401 ', ' 20141209 ', ' 1 ', ' 1 ', ' 138 ', ' 0 ', ' 0 ', ' 1 ', ' 1 ', ' 1 ', ' 0 ', ' 0 '],[' 44001 ', ' 20100428 ', ' 20141130 ', ' 1 ', ' 1 ', ' 85 ', ' 0 ', ' 0 ', ' 1 ', ' 0 ', ' 0 ', ' 0 ', ' 0 '],[' 45001 ', ' 1 ', ' 0 ', ' 20100429 ', ' 20141127 ', ' 1 ' ', ' 1 ', ' 128 ', ' 0 ', ' 0 ', ' 1 ', ' 24 ', ' 3 ', ' 0 ', ' 0 '],[' 50001 ', ' 0 ', ' 0 ', ' 20100506 ', ' 20141230 ', ' 1 ', ' 2 ', ' 67 ', ' 0 ', ' 0 ', '  44 ', ' 6 ', ' 1 ', ' 4 ', ' 1 '],[' 69001 ', ' 0 ', ' 0 ', ' 20100524 ', ' 20150129 ', ' 16 ', ' 20 ', ' 90 ', ' 2 ', ' 220 ', ' 236 ', ' 44 ', ' 18 ', ' 3 ', ' 2 '],[' 71001 ', ' 0 ', ' 2 ', ' 20100526 ', ' 20141224 ', ' 9 ', ' + ', ' 0 ', ' 0 ', ' arrays ', ' 4 ', ' 7 ', ' One ', ' Every_list ']]for: #add col num ber for I in range (len (every_list)): if i = = 0:continue Every_list[i] = str (i) + ":" +every_lis T[i] #remove col which value==0 for J in Every_list[1:]: If J.split (":") [-1] = = ' 0 ': #if float (j.spli T (': ') [-1]) = = 0:every_list.remove (j) Print Every_list

Because List[1:] produces a new copy, that is, to avoid the side traversal, while deleting the embarrassment, instead of traversing the copy, delete the original object.

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Python list pass-through delete element