Django conversion of unicode value to float doesn't work

Question

This is the part of my code where I need to convert a Unicode value to float using float(), but I got the exception invalid literal float()

print("before conversion ",request.POST['prix'])
prix=request.POST['prix']
prixConvert= float(prix)
print("after conversion ")
print(prixConvert)

Please post an example of a number you tried to convert, that causes the error. — C14L, Jun 02 '16 at 09:31
Please check.. this will happen if unicode contains a character other than a number.. — SuperNova, Jun 02 '16 at 09:56
please print request.POST['prix'] and show what you are trying to typecast to float — binu.py, Jun 02 '16 at 10:00
[This question](http://stackoverflow.com/questions/2308443/how-to-convert-a-numeric-string-with-place-value-commas-into-an-integer) might help. — Alasdair, Jun 02 '16 at 10:46

score 1 · Accepted Answer · answered Jun 02 '16 at 10:56

As per your comment under the question, your "number" actually contains a ,. That is not a valid character for a float() call. You need to convert that into a . first.

print("before: {}".format(request.POST['prix']))

prix = request.POST['prix'].replace(',', '.')
prixConvert = float(prix)

print("after conversion: {}".format(prixConvert))

And better, catch the error and tell the user to supply a valid string

try:
    prixConvert = float(prix)
except ValueError:
    print('That was not a valid float number.')

If your input is very unreliable, you can add more .replace() calls to "clean up" the input before converting, that way you may catch more numbers that are hidden within otherwise invalid input.

Django conversion of unicode value to float doesn't work

1 Answers1