Question

我在熊猫中有2列，像这样：

  column_a       column_b
     ok            pen
     ok            book
    0.615          C/H
    0.551          I/H

是否可以将这2列连接成这样的列？：

      column_c
        pen
        book
        0.615
        0.551

我已经尝试了很多方法，但是不能给我想要的结果，

Answer 1

有一个简单的解决方案：

df = pd.DataFrame({"column_a": ["ok", "ok", 0.615, 0.551], "column_b": ["pen", "book", "C/H", "I/H"]})

# Generate your condition
CONDITION = df["column_a"] == "ok"

#Initilize your new column to the first one.
df.loc[:,"together"] = df["column_a"]

# Add new column with the condition, called together
df.loc[CONDITION, "together"] = df["column_b"]


    column_a    column_b    together
0   ok          pen          pen
1   ok          book         book
2   0.615       C/H          NaN
3   0.551       I/H          NaN

因此，基本上，您创建第一列的副本，然后定义要更新值的条件。在这种情况下，我使用column_a =“ ok”。

Answer 2

如果您只需要它，可以手动进行：

df
   column_a column_b
0       ok      pen
1       ok     book
2    0.615      C/H
3    0.551      I/H

df['column_c'] = list(df.iloc[0:2, 1]) + list(df.iloc[2:,0])
df

 column_a column_b column_c
0    ok      pen      pen
1    ok     book     book
2  0.615     C/H    0.615
3  0.551     I/H    0.551

将两列数据串联到pandas中的一列中

2 个答案: