I am having issues with my code working properly and im stuck-CodePudding

I am having a problem with my code and getting it to work. Im not sure if im sorting this correctly. I am trying to sort with out lambda pandas or itemgetter.

Here is my code that I am having issues with.


with open('ManufacturerList.csv', 'r') as man_list:
    ml = csv.reader(man_list, delimiter=',')
    for row in ml:
        manufacturerList.append(row)
        print(row)
with open('PriceList.csv', 'r') as price_list:
    pl = csv.reader(price_list, delimiter=',')
    for row in pl:
        priceList.append(row)
        print(row)
with open('ManufacturerList.csv', 'r') as service_list:
    sl = csv.reader(service_list, delimiter=',')
    for row in sl:
        serviceList.append(row)
        print(row)

new_mfl = (sorted(manufacturerList, key='None'))
new_prl = (sorted(priceList, key='None'))
new_sdl = (sorted(serviceList, key='None'))

for x in range(0, len(new_mfl)):
    new_mfl[x].append(priceList[x][1])

for x in range(0, len(new_mfl)):
    new_mfl[x].append(serviceList[x][1])

new_list = new_mfl
inventoryList = (sorted(list, key=1))

i have tried to use the def function to try to get it to work but i dont know if im doing it right. This is what i tried.

def new_mfl(x):
    return x[0]


x.sort(key=new_mfl)

CodePudding user response：

You can do it like this:

def manufacturer_key(x):
    return x[0]

sorted_mfl = sorted(manufacturerList, key=manufacturer_key)

The key argument is the function that extracts the field of the CSV that you want to sort by.

CodePudding user response：

sort:

sorted_mfl = sorted(manufacturerList, key=lambda x: x[0])

there are different Dialects and Formatting Parameters that allow to handle input and output of data from comma separated value files; Maybe it could be used in a way with fewer statements using the correct delimiter which depends on the type of data you handle, this would be added to using built in methods like split for string data or another method to sort and manipulate lists, for example for single column data, delimiter=',' separate data by comma and it would iterate trough value by value and not as a list of lists when you call csv.reader

['9.310788653967691', '4.065746465800029', '6.6363356879192965', '7.279020237137884', '4.010297786910394'] 
['9.896092029283933', '7.553018448286675', '0.3268282119829197', '2.348011394854333', '3.964531054345021'] 
['5.078622663277619', '4.542467725728741', '3.743648062104161', '12.761916277286993', '9.164698479088221'] 

# out:
             column1             column2             column3             column4             column5
0  4.737897984379577   6.078414943611958  2.7021438955897095  5.8736388919905895   7.878958949784588
1  4.436982168483749  3.9453563399358544   12.66647791861843   5.323017508568736   4.156777982870004
2  4.798241413768279  12.690268531982028   9.638858110105895   7.881360524434767  4.2948334000783195

This is achieved because I am using lists that contain singular values, since for columns or lists that are of the form sorted_mfl = {'First Name' : ['name', 'name', 'name'], 'Seond Name ' : [...], 'ID':[...]}, new_prl = ['example', 'example', 'example'] new_sdl = [...] the data would be added by something like sorted_mfl new_prl new_sdl and since different modules are also used to set and manage comma separated files, you should add more information to your question like the data type you use or create a reproducible example using pandas, hope this can help.