Append pandas dataframe 与字典使用for循环

Question

I have the following dictionary and I want to add these in to a pandas dataframe:

crimes1 = {'SOUTHERN': 28445,
 'NORTHERN': 20100,
 'MISSION': 19503}

I create the blank dataframe with the column names I want:

column_names = ['Neighborhood', 'Count']
crimes2 = pd.DataFrame(columns=column_names)

Next I want to append the dataframe with my dictionary containing the keys and values above using a for loop:

for i, x in crimes1:
    crimes2 = crimes2.append({'Neighborhood': i}, {'Count': x}, ignore_index=True)

The error I get is ValueError: too many values to unpack (expected 2)

I can populate only one column when I do it separately but can't seem to get both in to the one dataframe. Any ideas on how to get this to work using the for loop above?

Answer 1

You are getting ValueError because you are not calling crimes1.items() which is require to iterate over the key, value pairs of dictionary. Simply, Use:

for i, x in crimes1.items():
    crimes2 = crimes2.append({'Neighborhood': i, 'Count': x}, ignore_index=True)

Result:

# print(crimes2)
  Neighborhood  Count
0     SOUTHERN  28445
1     NORTHERN  20100
2      MISSION  19503

Answer 2

You can use the map function

crimes2 = pd.DataFrame(map(list, crimes1.items()))

crimes2.columns = ['Neighborhood', 'Count']

Answer 3

You can try this.

crimes2 = pd.DataFrame(crimes1.items(), columns=['Neighborhood', 'Count'])
  Neighborhood  Count
0     SOUTHERN  28445
1     NORTHERN  20100
2      MISSION  19503