CODEWITHSUNDEEP
pythondataframe
Brenden Fujishige
Brenden Fujishige

Reputation: 1

How to find if a key does not exist in a dictionary?

I am importing some data from both a csv and an excel file using pandas, which are now dataframe types. And I am trying to use the csv to update the data in the excel file. I have the data being read correctly, but when I try to loop through the data to find if a certain key already exists, my if statement is not working.

for ID in update['Index']:
    if ID not in data['index']:

df1: data

Index Attr-1 Attr-2 Attr-3
01234 Blue   Car    Water
23456 Green  Truck  Lemonade
34567 Red    Bike   Milk Tea

df2: update

Index Attr-1 Attr-2 Attr-3
01234 Blue   Car    Milk Tea
34567 Yellow Truck  Lemonade
56789 Red    Bike   Milk Tea

actual result:

Index Attr-1 Attr-2 Attr-3
01234 Blue   Car    Milk Tea
01234 Blue   Car    Water
23456 Green  Truck  Lemonade
23456 Green  Truck  Lemonade
34567 Red    Bike   Milk Tea
34567 Yellow Truck  Lemonade
56789 Red    Bike   Milk Tea

desired result:

Index Attr-1 Attr-2 Attr-3
01234 Blue   Car    Milk Tea
23456 Green  Truck  Lemonade
34567 Yellow Truck  Lemonade
56789 Red    Bike   Milk Tea

My values are being duplicated because the values are not getting caught by the if statement. Not too sure what is going on? Any feedback/ideas are appreciated. Thanks.

Upvotes: 0

Views: 62

Answers (2)

Brenden Fujishige
Brenden Fujishige

Reputation: 1

The dataframe is not something I am allowed to use "in" on, which is why my for loop was not passing, so I created an array to hold the keys, data['index'].

`s = data['index'].tolist()
 for ID in update['index']:
  if ID not in s:`

Upvotes: 0

v.coder
v.coder

Reputation: 1932

Please see if this works, you need to check for the ID in index:

>>> data = pd.DataFrame({'Attr-1':['Blue','Green','Red']},index=['01234','23456','34567'])                                              
>>> update = pd.DataFrame({'Attr-1':['Blue','Yellow','Green']},index=['01234','34567','56789'])                                         
>>> for ID in update.index:                                                                                                             
...     if ID not in data.index:                                                                                                        
...         data = data.append(update.loc[ID])                                                                                          
... 
>>> data
        Attr-1
01234   Blue
23456  Green
34567    Red
56789  Green

Upvotes: 2

Related Questions