从列中的字典获取值。 AttributeError: 'NoneType' object 在值为“None”时没有属性“get”

Question

I have this df

     simbolo                                                     puntas           ultimoPrecio  
10   AE38             {'cantidadCompra': 79668.0, 'precioCompra': 60...           6080.00   
11   AL41C                                                         None             36.50   

and I get the first value from dict in "puntas" column.

p['Cant_Compra']=[x.get('cantidadCompra',0) for x in p['puntas']]

output:

     simbolo Cant_Compra  ultimoPrecio  
10    AE38     79668.0         6080.00 

but if value is None as line 11 appears next error message:

AttributeError: 'NoneType' object has no attribute 'get'

what can I do?

Answer 1

import ast
from io import StringIO

# sample data
s = """simbolo|puntas|ultimoPrecio  
AE38|{'cantidadCompra': 79668.0, 'precioCompra': 60}|6080.00   
AL41C|None|36.50"""
df = pd.read_csv(StringIO(s), sep='|')
df['puntas'] = df['puntas'].apply(ast.literal_eval)

# convert the dict column to a dataframe and assign the values to your column
df['Cant_Compra'] = pd.DataFrame(df['puntas'].to_dict()).T['cantidadCompra']


  simbolo                                           puntas  ultimoPrecio    \
0    AE38  {'cantidadCompra': 79668.0, 'precioCompra': 60}          6080.0   
1   AL41C                                             None            36.5   

  Cant_Compra  
0       79668  
1        None 

Answer 2

this works:

def fun(x):
  if x==None:
    return None
  return x['cantidadCompra']
p['Cant_Compra']=p['puntas'].apply(func=fun)