Home / Questions / 405130
Accepted
efueyo
Asked: 2021-11-10 07:08:06 +0800 CST 2021-11-10 07:08:06 +0800 CST

How can I fix this error: could not convert string to float: '1,448.94'?

  • 772

In the following DataFrame, the values ​​(1,531.20,...) are imported in the format object.

I try to convert them to the type float, applying the method .astype(float).

# Create DF from dict of lists/ndarrays
df = pd.DataFrame({'MSCI' : ['1,448.94', '1,480.57', '1,495.18', '1,531.20', '1,532.28'],
                       'Date' : ['2012-07-09','2012-07-10', '2012-07-11', '2012-07-12', '2012-07-13']})

df.set_index("Date", inplace = True)
df["MSCI"] = df.MSCI.astype(float)
df.info()

It returns me the error:

ValueError: could not convert string to float: '1,448.94'

I will appreciate suggestions to correct this error-

On the other hand, could I somehow get these numbers to be converted to the format on import float?

In the import I use pd.read_csv.

python

1 Answers

  1. Best Answer

    The problem is that the values ​​you have are not float, if you look closely they have "two commas", 1,448.94.

    If we assume that the comma is really a thousand separator, we could take all the values, remove the comma and convert them to float,

    import pandas as pd

# Create DF from dict of lists/ndarrays
df = pd.DataFrame({'MSCI' : ['1,448.94', '1,480.57', '1,495.18', '1,531.20', '1,532.28'],
                       'Date' : ['2012-07-09','2012-07-10', '2012-07-11', '2012-07-12', '2012-07-13']})

df.set_index("Date", inplace = True)
msci_vals = df['MSCI'].values
for i in range(len(msci_vals)):
  myVal = msci_vals[i].replace(",", "")
  msci_vals[i] = float(myVal)

    So now you have a list with all the values ​​of dataframethe float type.

    I hope I have been of help, anything you tell us!

    • 2