Reindexing error makes no sense

Question

I have `DataFrames` between 100k and 2m in size. the one I am dealing with for this question is this large, but note that I will have to do the same for the other frames: ``` >>> len(data) 357451 ``` now this file was created by compiling many files, so the index for it is really odd. So all I wanted to do was reindex it with `range(len(data))`, but I get this error: ``` >>> data.reindex(index=range(len(data))) Traceback (most recent call last): File "", line 1, in File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/frame.py", line 2542, in reindex fill_value, limit) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/frame.py", line 2618, in _reindex_index limit=limit) File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas/core/index.py", line 893, in reindex limit=limit) File "/opt/local/Library/Frameworks/Python.fr…

Accepted Answer

When it complains that `Reindexing only valid with uniquely valued Index`, it's not objecting that your new index isn't unique, it's objecting that your old one isn't.

For example:

```
>>> df = pd.DataFrame(range(5), index = [1,2,3,1,2])
>>> df
   0
1  0
2  1
3  2
1  3
2  4
>>> df.reindex(index=range(len(df)))
Traceback (most recent call last):
[...]
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.12.0.dev_0bd5e77-py2.7-linux-i686.egg/pandas/core/index.py", line 849, in get_indexer
    raise Exception('Reindexing only valid with uniquely valued Index '
Exception: Reindexing only valid with uniquely valued Index objects
```

but

```
>>> df.index = range(len(df))
>>> df
   0
0  0
1  1
2  2
3  3
4  4
```

Although I think I'd write

```
df.reset_index(drop=True)
```

instead.

Reindexing error makes no sense

Solution

Problem