Why am i getting this error code in python when calling a sum of 0

Question

Hello everyone! i am new to coding, and am trying to work on a script which uses information to calculate home many grams or micrograms a categorey contains based on the user imput. The below script works perfectly for any input besides one. when the user enters 1 as a choice, i get the following error code on the last line of the script: AttributeError: 'float' object has no attribute 'sum' what do i do to change this?

filename = '/Users/chelsie/Desktop/20220503_python_input_template.csv'
df = pd.read_csv(filename,delimiter=';',decimal=',',na_values=-9999.99)
# define columns, 1st line is header
cat = df["Category"]
subcat = df["Sub-category"]
m_p = df["mass per item (g)"]
m_mp = df["mass micrograms per item (g)"]
freq = df["Frequency as factor"]


#calculating number of children
print("Do You have any children?\n1) No\n2) Yes- 1\n3) Yes-2\n4) Yes-3")
val1 = int(input("Enter value: "))
# find all rows that contain a certain string 
info = df.loc[cat.str.contains("Children", case=False)]

idx=df.index[cat=='Children']

if val1 == 1:
    child=0.
    total+=0.
elif val1 == 2:
    child=1.
    #for i in range(len(idx)):
    total+= m_p.iloc[idx] *freq.iloc[idx]
elif val1 == 3:
    child=2.
    total +=  m_p.iloc[idx] *freq.iloc[idx] 
elif val1 == 4:  
    child=3.
    total +=  m_p.iloc[idx] *freq.iloc[idx] 
else:
    print('error')


total = total.sum()*child
#    #calculate number of grams per child 

Answer 1

这可能是因为在m_p != 1情况下， total是一些具有 .sum() 方法的熊猫对象，而在val1 == 1情况下， total是浮点数（浮点数没有 .sum() 方法）。

Answer 2

in the other conditions, you have the line total += m_p.iloc[idx]... . Here, m_p.iloc[] returns a Pandas Series . When this line is executed, the total variable now holds a Pandas Series object which has a .sum() method.

But in the first condition, you are just adding a float to total . The total variable remains a float variable which of course doesnt have a .sum() method. The exact error you are getting.

To fix this, you can initialize total as a Series :

total = pd.Series([0.])