formatting the float for series float datatype-CodePudding

when trying below code get the error unsupported format string passed to Series.float How to solve this problem

Code tried:

df['a3'] = "the value is {:.2f}".format(df['a2'])

Here , df['a2'] consists of values [0.0,1.0,2.0] and its dtype is float64.

How do i rectify this format error, please help!

CodePudding user response：

You can't use str.format like that. Instead, you can use apply() to do this for every item in the a2 column:

df['a3'] = df['a2'].apply(lambda x: "the value is {:.2f}".format(x))

Output:

>>> df
    a2                 a3
0  0.0  the value is 0.00
1  0.1  the value is 0.10
2  0.2  the value is 0.20

Bonus: Now, a trick, which might work for you (but might not) and which might be a bit faster would be to to do something like this:

df['a4'] = 'the value is '   df['a2'].astype(str)   '!!'

Output:

>>> df
    a2                 a3                  a4
0  0.0  the value is 0.00  the value is 0.0!!
1  0.1  the value is 0.10  the value is 0.1!!
2  0.2  the value is 0.20  the value is 0.2!!