Replace comma with dot Pandas

Question

Given the following array, I want to replace commas with dots:

array([\'0,140711\', \'0,140711\', \'0,0999\', \'0,0999\', \'0,001\', \'0,001\',
       \'0,14         


        

Answer 1

You need to assign the result of your operate back as the operation isn't inplace, besides you can use apply or stack and unstack with vectorised str.replace to do this quicker:

In [5]:
df.apply(lambda x: x.str.replace(',','.'))

Out[5]:
          1-8        1-7
H0   0.140711   0.140711
H1     0.0999     0.0999
H2      0.001      0.001
H3   0.140711   0.140711
H4   0.140711   0.140711
H5   0.140711   0.140711
H6          0          0
H7          0          0
H8   0.140711   0.140711
H9   0.140711   0.140711
H10  0.140711  0.1125688
H11  0.140711  0.1125688
H12  0.140711  0.1125688
H13  0.140711  0.1125688
H14  0.140711   0.140711
H15  0.140711   0.140711
H16  0.140711   0.140711
H17  0.140711   0.140711
H18  0.140711   0.140711
H19  0.140711   0.140711
H20  0.140711   0.140711
H21  0.140711   0.140711
H22  0.140711   0.140711
H23  0.140711   0.140711

In [4]:    
df.stack().str.replace(',','.').unstack()

Out[4]:
          1-8        1-7
H0   0.140711   0.140711
H1     0.0999     0.0999
H2      0.001      0.001
H3   0.140711   0.140711
H4   0.140711   0.140711
H5   0.140711   0.140711
H6          0          0
H7          0          0
H8   0.140711   0.140711
H9   0.140711   0.140711
H10  0.140711  0.1125688
H11  0.140711  0.1125688
H12  0.140711  0.1125688
H13  0.140711  0.1125688
H14  0.140711   0.140711
H15  0.140711   0.140711
H16  0.140711   0.140711
H17  0.140711   0.140711
H18  0.140711   0.140711
H19  0.140711   0.140711
H20  0.140711   0.140711
H21  0.140711   0.140711
H22  0.140711   0.140711
H23  0.140711   0.140711

the key thing here is to assign back the result:

df = df.stack().str.replace(',','.').unstack()

Answer 2

If you are reading in with read_csv, you can specify how it interprets decimals with the decimal parameter.

e.g.

your_df = pd.read_csv('/your_path/your_file.csv',sep=';',decimal=',')

From the man pages:

thousands : str, optional Thousands separator.

decimal : str, default ‘.’ Character to recognize as decimal point (e.g. use ‘,’ for European data).