python中的表函数

我有两个变量

a                   b
Less than 5        Yes
Less than 5        No
Less than 5        Yes
Less than 5        No
Less than 5        Yes
Greater than 5     No
Greater than 5     Yes
Greater than 5     No
Greater than 5     Yes

我想要一张桌子，上面有

                 Yes     No
Less than 5       3      2
Greater than 5    2      2

我基本上想要python中R的表函数

有人能帮我做这件事吗

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谢谢

假设列表a和b的长度始终相同

distinct = set(a)
for type in distinct:
   yes = [b[i] for i in range(len(b)) if a[i] == type].count('yes')
   no = [b[i] for i in range(len(b)) if a[i] == type].count('no')
   print type, yes, no

花式格式不包括在内

import petl

a = ['Less than 5', 'Less than 5','Less than 5','Less than 5','Less than 5',
     'Greater than 5','Greater than 5','Greater than 5','Greater than 5',]
b = ['Yes', 'No', 'Yes', 'No', 'Yes', 'No', 'Yes', 'No', 'Yes']
cols = [a, b]
table = petl.fromcolumns(cols)

yes_table = petl.addfield(table, 'Yes_addition', lambda rec: 1 if rec['f1'] == 'Yes' else 0)
yes_table = petl.aggregate(yes_table, 'f0', sum, 'Yes_addition')
yes_table = petl.rename(yes_table, 'value', 'Yes')

no_table = petl.addfield(table, 'No_addition', lambda rec: 0 if rec['f1'] == 'Yes' else 1)
no_table = petl.aggregate(no_table, 'f0', sum, 'No_addition')
no_table = petl.rename(no_table, 'value', 'No')

joined = petl.join(yes_table, no_table, key='f0')

print petl.lookall(joined)
as_dictionary = petl.dicts(joined)

上述输出将产生以下结果（以及as_dictionary变量将是一个可以在代码中其他地方轻松使用的字典）：

别忘了安装petl

pip install petl

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最好的做法是提供一个最小的可复制示例。

pip install petl