Pandas - 複数の列の値をマージする

Question

作成したときに値が複数の列に分割されたDataFrameがあります。私は2〜4列を1つにマージしたいと思います。

fish_frame:       0  1  2   3 \ 
0     735-8  NaN  NaN  NaN 
1      NaN  NaN  NaN LIVE WGT 
2     GBE COD  NaN  NaN  600 
3     GBW COD  NaN 11,189  NaN 
4     GOM COD  NaN  0  NaN 
5     POLLOCK  NaN  NaN  1,103 
6     WHAKE  NaN  NaN  12 
7    GBE HADDOCK  NaN 10,730  NaN 
8    GBW HADDOCK  NaN 64,147  NaN 
9    GOM HADDOCK  NaN  0  NaN 
10    REDFISH  NaN  NaN   0 
11   WITCH FLOUNDER  NaN  370  NaN 
12     PLAICE  NaN  NaN  622 
13  GB WINTER FLOUNDER 54,315  NaN  NaN 
14 GOM WINTER FLOUNDER  653  NaN  NaN 
15 SNEMA WINTER FLOUNDER 14,601  NaN  NaN 
16   GB YELLOWTAIL  NaN 1,663  NaN 
17  SNEMA YELLOWTAIL  NaN 1,370  NaN 
18  CCGOM YELLOWTAIL 1,812  NaN  NaN 

          4  6  package_deal_column Package_Price 
0       NaN NaN Package Deal - $40,753.69   nan 
1       NaN TOTAL Package Deal - $40,753.69   nan 
2       NaN NaN Package Deal - $40,753.69   None 
3       NaN NaN Package Deal - $40,753.69   None 
4 Package Deal - $40,753.69 None Package Deal - $40,753.69   None 
5       NaN NaN Package Deal - $40,753.69   None 
6       NaN NaN Package Deal - $40,753.69   None 
7       NaN NaN Package Deal - $40,753.69   None 
8       NaN NaN Package Deal - $40,753.69   None 
9       NaN NaN Package Deal - $40,753.69   None 
10      NaN NaN Package Deal - $40,753.69   None 
11      NaN NaN Package Deal - $40,753.69   None 
12      NaN NaN Package Deal - $40,753.69   None 
13      NaN None Package Deal - $40,753.69   None 
14      NaN None Package Deal - $40,753.69   None 
15      NaN None Package Deal - $40,753.69   None 
16      NaN NaN Package Deal - $40,753.69   None 
17      NaN NaN Package Deal - $40,753.69   None 
18      NaN None Package Deal - $40,753.69   None 

ご覧のとおり、weightの値は複数の列に分割されています。

私はこの答えの方向（pandas merge columns in same dataframe）に続き、試してみました：

pd.DataFrame({'Column 2': pd.concat([fish_frame[1], fish_frame[2], fish_frame[3]])}).sort_index() 

をそれはそれらをマージすることに成功しませんでした。コマンドを間違って使用したか、問題がより具体的であるかどうかではわかりません。

また、私は、これはそれを解決するとは思わなかったが、私は試してくださいでした：

fish_frame = fish_frame.dropna(axis=1, how='all')が、それはDFを変化させませんでした。

これを解決する助けがあれば感謝します。

fish_frame = fish_frame.set_index(0).stack()を行うと、生成何を：

fish_frame: 735-8     package_deal_column Package Deal - $40,753.69 
         Package_Price        nan 
NaN     3          LIVE WGT 
         6           TOTAL 
         package_deal_column Package Deal - $40,753.69 
         Package_Price        nan 
GBE COD    3           600 
         package_deal_column Package Deal - $40,753.69 
GBW COD    2           11,189 
         package_deal_column Package Deal - $40,753.69 
GOM COD    2            0 
         4      Package Deal - $40,753.69 
         package_deal_column Package Deal - $40,753.69 
POLLOCK    3           1,103 
         package_deal_column Package Deal - $40,753.69 
WHAKE     3            12 
         package_deal_column Package Deal - $40,753.69 
GBE HADDOCK   2           10,730 
         package_deal_column Package Deal - $40,753.69 
GBW HADDOCK   2           64,147 
         package_deal_column Package Deal - $40,753.69 
GOM HADDOCK   2            0 
         package_deal_column Package Deal - $40,753.69 
REDFISH    3            0 
         package_deal_column Package Deal - $40,753.69 
WITCH FLOUNDER   2           370 
         package_deal_column Package Deal - $40,753.69 
PLAICE     3           622 
         package_deal_column Package Deal - $40,753.69 
GB WINTER FLOUNDER  1           54,315 
         package_deal_column Package Deal - $40,753.69 
GOM WINTER FLOUNDER 1           653 
         package_deal_column Package Deal - $40,753.69 
SNEMA WINTER FLOUNDER 1           14,601 
         package_deal_column Package Deal - $40,753.69 
GB YELLOWTAIL   2           1,663 
         package_deal_column Package Deal - $40,753.69 
SNEMA YELLOWTAIL  2           1,370 
         package_deal_column Package Deal - $40,753.69 
CCGOM YELLOWTAIL  1           1,812 
         package_deal_column Package Deal - $40,753.69 

Answer 1

使用​​とstack：

あなたの列ヘッダのごDTYPEが整数であるか、STR場合によっては：

df.set_index('0').stack() 

OR

を

df.set_index(0).stack() 

出力：

0      
NaN     3 LIVE WGT 
GBE COD    3   600 
GBW COD    2  11,189 
GOM COD    2   0 
POLLOCK    3  1,103 
WHAKE     3   12 
GBE HADDOCK   2  10,730 
GBW HADDOCK   2  64,147 
GOM HADDOCK   2   0 
REDFISH    3   0 
WITCH FLOUNDER   2   370 
PLAICE     3   622 
GB WINTER FLOUNDER  1  54,315 
GOM WINTER FLOUNDER 1   653 
SNEMA WINTER FLOUNDER 1  14,601 
GB YELLOWTAIL   2  1,663 
SNEMA YELLOWTAIL  2  1,370 
CCGOM YELLOWTAIL  1  1,812 
dtype: object 

は、などの名前を変更し、さらに行く..

df.set_index('0').stack().reset_index(name='weights').drop('level_1',axis=1) 

出力： `KeyError例外：「0 '（ '0'）`生成し、それをしようと

     0 weights 
0      NaN LIVE WGT 
1     GBE COD  600 
2     GBW COD 11,189 
3     GOM COD   0 
4     POLLOCK  1,103 
5     WHAKE  12 
6    GBE HADDOCK 10,730 
7    GBW HADDOCK 64,147 
8    GOM HADDOCK   0 
9     REDFISH   0 
10   WITCH FLOUNDER  370 
11     PLAICE  622 
12  GB WINTER FLOUNDER 54,315 
13 GOM WINTER FLOUNDER  653 
14 SNEMA WINTER FLOUNDER 14,601 
15   GB YELLOWTAIL  1,663 
16  SNEMA YELLOWTAIL  1,370 
17  CCGOM YELLOWTAIL  1,812