Converting Floats to String in Mixed Type DF Column Uses Scientific Notation

I have a dataframe with a column that is being read in with mixed types.

df = pd.DataFrame({'mix':['a',6,0.23423,False, 0.000023425]})

I want to convert the column to strings, but when I do so, any long decimals get converted to scientific notation. How do I keep all decimals in decimal notation?

df.astype(str)
    mix
0   a
1   6
2   0.23423
3   False
4   2.3425e-11

Desired output:

    mix
0   a
1   6
2   0.23423
3   False
4   0.000000000023425

You can use the numpy format_float_positional function, as follows.

import numpy as np

df = pd.DataFrame({'mix':['a',6,0.23423,False, 0.000000000023425]})

def custom_str(x):
    if isinstance(x, float):
        return np.format_float_positional(x)
    return str(x)

df['mix'].apply(custom_str)

Output:

0                    a
1                    6
2              0.23423
3                False
4    0.000000000023425