Convert number strings with commas in pandas DataFrame to float

If you're reading in from csv then you can use the thousands arg:

df.read_csv('foo.tsv', sep='\t', thousands=',')

This method is likely to be more efficient than performing the operation as a separate step.

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You need to set the locale first:

In [ 9]: import locale

In [10]: from locale import atof

In [11]: locale.setlocale(locale.LC_NUMERIC, '')
Out[11]: 'en_GB.UTF-8'

In [12]: df.applymap(atof)
Out[12]:
      0        1
0  1200  4200.00
1  7000    -0.03
2     5     0.00

You can convert one column at a time like this :

df['colname'] = df['colname'].str.replace(',', '').astype(float)