Python删除所有在字段中具有共同价值的行

Question

我有4个字段的数据行

aaaa bbb1 cccc dddd  
aaaa bbb2 cccc dddd  
aaaa bbb3 cccc eeee  
aaaa bbb4 cccc ffff  
aaaa bbb5 cccc gggg  
aaaa bbb6 cccc dddd    

请多多包涵.

第一个和第三个字段总是相同的 - 但我不需要它们,第四个字段可以相同或不同.问题是,我只想要不共享公共字段的第2和第4个字段.例如,如上所述

bbb3 eeee  
bbb4 ffff    
bbb5 gggg    

现在我并不是指重复数据删除,因为它会留下其中一个条目.如果第4个字段与另一行共享一个值,我不希望任何行具有该值.

最简单的道歉再次询问什么可能是简单的.

Answer 1

干得好:

from collections import defaultdict

LINES = """\
aaaa bbb1 cccc dddd
aaaa bbb2 cccc dddd
aaaa bbb3 cccc eeee
aaaa bbb4 cccc ffff
aaaa bbb5 cccc gggg
aaaa bbb6 cccc dddd""".split('\n')

# Count how many lines each unique value of the fourth field appears in.
d_counts = defaultdict(int)
for line in LINES:
    a, b, c, d = line.split()
    d_counts[d] += 1

# Print only those lines with a unique value for the fourth field.
for line in LINES:
    a, b, c, d = line.split()
    if d_counts[d] == 1:
        print b, d

# Prints
# bbb3 eeee
# bbb4 ffff
# bbb5 gggg