您可以使用一个集合，它是唯一元素的无序集合，以保持“其他列的顺序不变”：

other_columns = list(set(df.columns).difference(["mean"])) #[0, 1, 2, 3, 4]

然后，可以通过以下方式使用lambda将特定列移动到前面：

In [1]: import numpy as np                                                                               

In [2]: import pandas as pd                                                                              

In [3]: df = pd.DataFrame(np.random.rand(10, 5))                                                         

In [4]: df["mean"] = df.mean(1)                                                                          

In [5]: move_col_to_front = lambda df, col: df[[col]+list(set(df.columns).difference([col]))]            

In [6]: move_col_to_front(df, "mean")                                                                    
Out[6]: 
       mean         0         1         2         3         4
0  0.697253  0.600377  0.464852  0.938360  0.945293  0.537384
1  0.609213  0.703387  0.096176  0.971407  0.955666  0.319429
2  0.561261  0.791842  0.302573  0.662365  0.728368  0.321158
3  0.518720  0.710443  0.504060  0.663423  0.208756  0.506916
4  0.616316  0.665932  0.794385  0.163000  0.664265  0.793995
5  0.519757  0.585462  0.653995  0.338893  0.714782  0.305654
6  0.532584  0.434472  0.283501  0.633156  0.317520  0.994271
7  0.640571  0.732680  0.187151  0.937983  0.921097  0.423945
8  0.562447  0.790987  0.200080  0.317812  0.641340  0.862018
9  0.563092  0.811533  0.662709  0.396048  0.596528  0.348642

In [7]: move_col_to_front(df, 2)                                                                         
Out[7]: 
          2         0         1         3         4      mean
0  0.938360  0.600377  0.464852  0.945293  0.537384  0.697253
1  0.971407  0.703387  0.096176  0.955666  0.319429  0.609213
2  0.662365  0.791842  0.302573  0.728368  0.321158  0.561261
3  0.663423  0.710443  0.504060  0.208756  0.506916  0.518720
4  0.163000  0.665932  0.794385  0.664265  0.793995  0.616316
5  0.338893  0.585462  0.653995  0.714782  0.305654  0.519757
6  0.633156  0.434472  0.283501  0.317520  0.994271  0.532584
7  0.937983  0.732680  0.187151  0.921097  0.423945  0.640571
8  0.317812  0.790987  0.200080  0.641340  0.862018  0.562447
9  0.396048  0.811533  0.662709  0.596528  0.348642  0.563092

一种简单的方法是用列列表重新分配数据帧，根据需要重新排列。

这就是你现在拥有的：

In [6]: df
Out[6]:
          0         1         2         3         4      mean
0  0.445598  0.173835  0.343415  0.682252  0.582616  0.445543
1  0.881592  0.696942  0.702232  0.696724  0.373551  0.670208
2  0.662527  0.955193  0.131016  0.609548  0.804694  0.632596
3  0.260919  0.783467  0.593433  0.033426  0.512019  0.436653
4  0.131842  0.799367  0.182828  0.683330  0.019485  0.363371
5  0.498784  0.873495  0.383811  0.699289  0.480447  0.587165
6  0.388771  0.395757  0.745237  0.628406  0.784473  0.588529
7  0.147986  0.459451  0.310961  0.706435  0.100914  0.345149
8  0.394947  0.863494  0.585030  0.565944  0.356561  0.553195
9  0.689260  0.865243  0.136481  0.386582  0.730399  0.561593

In [7]: cols = df.columns.tolist()

In [8]: cols
Out[8]: [0L, 1L, 2L, 3L, 4L, 'mean']

按任意方式重新排列列。这是我将最后一个元素移动到第一个位置的方式：

In [12]: cols = cols[-1:] + cols[:-1]

In [13]: cols
Out[13]: ['mean', 0L, 1L, 2L, 3L, 4L]

然后重新排序数据帧，如下所示：

In [16]: df = df[cols]  #    OR    df = df.ix[:, cols]

In [17]: df
Out[17]:
       mean         0         1         2         3         4
0  0.445543  0.445598  0.173835  0.343415  0.682252  0.582616
1  0.670208  0.881592  0.696942  0.702232  0.696724  0.373551
2  0.632596  0.662527  0.955193  0.131016  0.609548  0.804694
3  0.436653  0.260919  0.783467  0.593433  0.033426  0.512019
4  0.363371  0.131842  0.799367  0.182828  0.683330  0.019485
5  0.587165  0.498784  0.873495  0.383811  0.699289  0.480447
6  0.588529  0.388771  0.395757  0.745237  0.628406  0.784473
7  0.345149  0.147986  0.459451  0.310961  0.706435  0.100914
8  0.553195  0.394947  0.863494  0.585030  0.565944  0.356561
9  0.561593  0.689260  0.865243  0.136481  0.386582  0.730399

使用T怎么样？

df = df.T.reindex(['mean', 0, 1, 2, 3, 4]).T

书中最黑客的方法

df.insert(0, "test", df["mean"])
df = df.drop(columns=["mean"]).rename(columns={"test": "mean"})

我自己也遇到了一个类似的问题，只是想补充一下我已经解决的问题。我喜欢用于更改列顺序的reindex_axis（）方法。这是有效的：

df = df.reindex_axis(['mean'] + list(df.columns[:-1]), axis=1)

另一种基于@Jorge评论的方法：

df = df.reindex(columns=['mean'] + list(df.columns[:-1]))

虽然reindex_axis在微基准测试中似乎比reindex稍快，但我认为我更喜欢后者，因为它的直接性。

您可以使用可用于两个轴的重新索引：

df
#           0         1         2         3         4      mean
# 0  0.943825  0.202490  0.071908  0.452985  0.678397  0.469921
# 1  0.745569  0.103029  0.268984  0.663710  0.037813  0.363821
# 2  0.693016  0.621525  0.031589  0.956703  0.118434  0.484254
# 3  0.284922  0.527293  0.791596  0.243768  0.629102  0.495336
# 4  0.354870  0.113014  0.326395  0.656415  0.172445  0.324628
# 5  0.815584  0.532382  0.195437  0.829670  0.019001  0.478415
# 6  0.944587  0.068690  0.811771  0.006846  0.698785  0.506136
# 7  0.595077  0.437571  0.023520  0.772187  0.862554  0.538182
# 8  0.700771  0.413958  0.097996  0.355228  0.656919  0.444974
# 9  0.263138  0.906283  0.121386  0.624336  0.859904  0.555009

df.reindex(['mean', *range(5)], axis=1)

#        mean         0         1         2         3         4
# 0  0.469921  0.943825  0.202490  0.071908  0.452985  0.678397
# 1  0.363821  0.745569  0.103029  0.268984  0.663710  0.037813
# 2  0.484254  0.693016  0.621525  0.031589  0.956703  0.118434
# 3  0.495336  0.284922  0.527293  0.791596  0.243768  0.629102
# 4  0.324628  0.354870  0.113014  0.326395  0.656415  0.172445
# 5  0.478415  0.815584  0.532382  0.195437  0.829670  0.019001
# 6  0.506136  0.944587  0.068690  0.811771  0.006846  0.698785
# 7  0.538182  0.595077  0.437571  0.023520  0.772187  0.862554
# 8  0.444974  0.700771  0.413958  0.097996  0.355228  0.656919
# 9  0.555009  0.263138  0.906283  0.121386  0.624336  0.859904