如何在dataframe中获取给定值的行数和列数

If值 search_row 和 search_column 在所有数据使用中都是唯一的 np.where 对于位置和选择方式 DataFrame.iloc :

df = pd.DataFrame({'A':list('abcdef'),
                   'B':[4,5,4,5,500,4],
                   'C':[7,8,9,4,2,3],
                   'D':[1,300,5,7,1,0],
                   'E':[5,3,6,9,2,4],
                   'F':list('aaabbb')}, index = [1] * 6)
df.columns = ['A'] * 6
print (df)
   A    A  A    A  A  A
1  a    4  7    1  5  a
1  b    5  8  300  3  a
1  c    4  9    5  6  a
1  d    5  4    7  9  b
1  e  500  2    1  2  b
1  f    4  3    0  4  b

a = np.where(df == 500)[0]
b = np.where(df == 300)[1]
print (a)
[4]
print (b)
[3]

c = df.iloc[a[0],b[0]]
print (c)
1

但如果可以复制值,请仅选择第一次出现,因为 np。哪里 使用返回数组 length > 1 :

a = np.where(df == 5)[0]
b = np.where(df == 2)[1]
print (a)
[0 1 2 3]
print (b)
[2 4]

c = df.iloc[a[0],b[0]]
print (c)
7

a = np.where(df == 2)[0]
b = np.where(df == 5)[1]
print (a)
[4 4]
print (b)
[4 1 3 1]

c = df.iloc[a[0],b[0]]
print (c)
2