Cannot convert the series to <class 'float'>-CodePudding

I have a pandas table and I want to do the following mathematics operation:

|label|  area | equivalent_diameter|  mean_intensity|  solidity|
---------------------------------------------------------------
   1    1011       35.878199           255.0          0.863365:
   2    107        11.672045           255.0          0.849206
   3     8         3.191538            76.0           0.800000
   4    18         4.787307            255.0          0.720000
   5    110        11.834541           255.0          0.769231
----------------------------------------------------------------

Basically I want to:

df['area'] = math.sqrt(df['area]/math.pi)

TypeError: cannot convert the series to <class 'float'>

What I did and does not solve the problem:

new_data = df['area'].apply(lambda x: float(x))

# and then:

new_x = new_data/math.pi
new_y = math.sqrt(new_x)

still given the same error.

CodePudding user response：

Try with numpy:

import numpy as np
df['area'] = np.sqrt(df['area']/np.pi)

CodePudding user response：

You can use the List comprehension and then equal the data to your data frame. Please try the below code:

import pandas as pd
import math
d = {'label': [1, 2, 3, 4, 5], 'area': [1011, 107, 8, 18, 110],
 'equivalent_diameter': [35.878199, 11.672045, 3.191538, 4.787307, 11.834541],
 'mean_intensity': [255.0, 255.0, 76.0, 255.0, 255.0],
 'solidity': [0.863365, 0.849206, 0.800000, 0.720000, 0.769231]}
df = pd.DataFrame(data=d)
data = df['area']/math.pi
df['area'] = [math.sqrt(i) for i in data]
print(df)