pandas - 您可以防止df.append()的自动字母顺序吗？

我试图将数据追加到日志中，其中列的顺序不是字母顺序，但是在逻辑上是合理的。

Org_Goals_1  Calc_Goals_1  Diff_Goals_1   Org_Goals_2 Calc_Goals_2 Diff_Goals_2

我正在根据不同的变量进行多次计算，并在每次运行后通过附加值字典来记录结果。有没有办法防止df.append（）函数按字母顺序对列进行排序？

最佳答案

似乎您必须在执行追加操作后对列进行重新排序：

In [25]:
# assign the appended dfs to merged
merged = df1.append(df2)
# create a list of the columns in the order you desire
cols = list(df1) + list(df2)
# assign directly
merged.columns = cols
# column order is now as desired
merged.columns
Out[25]:
Index(['Org_Goals_1', 'Calc_Goals_1', 'Diff_Goals_1', 'Org_Goals_2', 'Calc_Goals_2', 'Diff_Goals_2'], dtype='object')

例：

In [26]:

df1 = pd.DataFrame(columns=['Org_Goals_1','Calc_Goals_1','Diff_Goals_1'], data = randn(5,3))
df2 = pd.DataFrame(columns=['Org_Goals_2','Calc_Goals_2','Diff_Goals_2'], data=randn(5,3))
merged = df1.append(df2)
cols = list(df1) + list(df2)
merged.columns = cols
merged
Out[26]:
   Org_Goals_1  Calc_Goals_1  Diff_Goals_1  Org_Goals_2  Calc_Goals_2  \
0     0.028935           NaN     -0.687143          NaN      1.528579
1     0.943432           NaN     -2.055357          NaN     -0.720132
2     0.035234           NaN      0.020756          NaN      1.556319
3     1.447863           NaN      0.847496          NaN     -1.458852
4     0.132337           NaN     -0.255578          NaN     -0.222660
0          NaN      0.131085           NaN     0.850022           NaN
1          NaN     -1.942110           NaN     0.672965           NaN
2          NaN      0.944052           NaN     1.274509           NaN
3          NaN     -1.796448           NaN     0.130338           NaN
4          NaN      0.961545           NaN    -0.741825           NaN

   Diff_Goals_2
0           NaN
1           NaN
2           NaN
3           NaN
4           NaN
0      0.727619
1      0.022209
2     -0.350757
3      1.116637
4      1.947526

concat也对列进行相同的alpha排序，因此看起来您必须在追加后重新排序。

编辑

另一种方法是使用join：

In [32]:

df1.join(df2)
Out[32]:
   Org_Goals_1  Calc_Goals_1  Diff_Goals_1  Org_Goals_2  Calc_Goals_2  \
0     0.163745      1.608398      0.876040     0.651063      0.371263
1    -1.762973     -0.471050     -0.206376     1.323191      0.623045
2     0.166269      1.021835     -0.119982     1.005159     -0.831738
3    -0.400197      0.567782     -1.581803     0.417112      0.188023
4    -1.443269     -0.001080      0.804195     0.480510     -0.660761

   Diff_Goals_2
0     -2.723280
1      2.463258
2      0.147251
3      2.328377
4     -0.248114

关于pandas - 您可以防止df.append()的自动字母顺序吗？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/27749276/