使用列表从 pandas DataFrame 中选择行

Question

我有如下列表

[[1, 2], [1, 3]]

DataFrame 类似于

我想要一个 DataFrame，如果 A 列中的值等于任何嵌套列表的第一个元素，并且相应行的 B 列中的值等于同一嵌套列表的第二个元素.

因此生成的 DataFrame 应该是

  A B C
0 1 2 4
2 1 3 0

Answer 1

下面的代码确实需要你：

tmp_filter = pandas.DataFrame(None) #The dataframe you want
# Create your list and your dataframe
tmp_list = [[1, 2], [1, 3]]
tmp_df = pandas.DataFrame([[1,2,4],[0,1,2],[1,3,0]], columns = ['A','B','C'])

#This function will pass the df pass columns by columns and
#only keep the columns with the value you want
def pass_true_df(df, cond):
    for i, c in enumerate(cond):
        df = df[df.iloc[:,i] == c]
    return df

# Pass through your list and add the row you want to keep
for i in tmp_list:
    tmp_filter = pandas.concat([tmp_filter, pass_true_df(tmp_df, i)])

Answer 2

import pandas
df = pandas.DataFrame([[1,2,4],[0,1,2],[1,3,0],[0,2,5],[1,4,0]],
                      columns = ['A','B','C'])
filt = pandas.DataFrame([[1, 2], [1, 3],[0,2]],
                          columns = ['A','B'])

accum = []

#grouped to-filter
data_g = df.groupby('A')
for k2,v2 in data_g:
    accum.append(v2[v2.B.isin(filt.B[filt.A==k2])])

print(pandas.concat(accum))

结果：

（为了测试，我把数据和过滤器弄得复杂了一点。）

使用列表从 pandas DataFrame 中选择行

Selecting rows from pandas DataFrame using a list

python

pandas