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setting column names has no effect

See original GitHub issue

I am doing a table join and would like to rename columns in the resulting table acs afterwards. So I set:

acs.columns = ["chr","start", "end", "rep1", "rep2"]

It allegedly works:

In [11]: acs.columns
Out[11]: ['chr', 'start', 'end', 'rep1', 'rep2']

But not really:

In [12]: acs.head()
Out[12]:
    chr  start    end  counts_x  counts_y
0  chr1  15765  17765         5         1
...

Issue Analytics

State:
Created 8 years ago
Comments:6 (5 by maintainers)

Top GitHub Comments

1reaction

TomAugspurgercommented, Nov 6, 2015

@DSLituiev df = df.rename(columns=dict(zip(df.columns, new_columns))), slightly inconvenient but not too bad. dask has a few more things to track than pandas.

0reactions

mrocklincommented, Mar 24, 2017

It looks like this works now?

In [1]: import dask.dataframe as dd

In [2]: df = dd.demo.daily_stock('GOOG', '2008', '2010', freq='1s', 
   ...:                          random_state=1234)

In [3]: 

In [3]: df
Out[3]: 
Dask DataFrame Structure:
                       close     high      low     open
npartitions=505                                        
2008-01-02 09:00:00  float64  float64  float64  float64
2008-01-03 09:00:00      ...      ...      ...      ...
...                      ...      ...      ...      ...
2009-12-31 09:00:00      ...      ...      ...      ...
2009-12-31 16:00:00      ...      ...      ...      ...
Dask Name: from-delayed, 1010 tasks

In [4]: df.columns = list(map(str.upper, df.columns))

In [5]: df
Out[5]: 
Dask DataFrame Structure:
                       CLOSE     HIGH      LOW     OPEN
npartitions=505                                        
2008-01-02 09:00:00  float64  float64  float64  float64
2008-01-03 09:00:00      ...      ...      ...      ...
...                      ...      ...      ...      ...
2009-12-31 09:00:00      ...      ...      ...      ...
2009-12-31 16:00:00      ...      ...      ...      ...
Dask Name: rename, 1515 tasks

In [6]: df.head()
Out[6]: 
                       CLOSE     HIGH      LOW     OPEN
timestamp                                              
2008-01-02 09:00:00  692.889  692.889  692.840  692.871
2008-01-02 09:00:01  692.776  692.868  692.776  692.868
2008-01-02 09:00:02  692.737  692.818  692.737  692.797
2008-01-02 09:00:03  692.632  692.711  692.632  692.711
2008-01-02 09:00:04  692.521  692.637  692.521  692.637