python pandas数据框列转换为dict键和值

Question

I have a pandas data frame with multiple columns and I would like to construct a dict from two columns: one as the dict's keys and the other as the dict's values. How can I do that?

Dataframe:

           area  count
co tp
DE Lake      10      7
Forest       20      5
FR Lake      30      2
Forest       40      3

I need to define area as key, count as value in dict. Thank you in advance.

Answer 1

如果lakes是您的DataFrame ，您可以执行以下操作

area_dict = dict(zip(lakes.area, lakes.count))

Answer 2

With pandas it can be done as:

If lakes is your DataFrame:

area_dict = lakes.to_dict('records')

Answer 3

You can also do this if you want to play around with pandas. However, I like punchagan's way.

# replicating your dataframe
lake = pd.DataFrame({'co tp': ['DE Lake', 'Forest', 'FR Lake', 'Forest'], 
                 'area': [10, 20, 30, 40], 
                 'count': [7, 5, 2, 3]})
lake.set_index('co tp', inplace=True)

# to get key value using pandas
area_dict = lake.set_index('area').T.to_dict('records')[0]
print(area_dict)

output: {10: 7, 20: 5, 30: 2, 40: 3}

Answer 4

If 'lakes' is your DataFrame, you can also do something like:

# Your dataframe
lakes = pd.DataFrame({'co tp': ['DE Lake', 'Forest', 'FR Lake', 'Forest'], 
                 'area': [10, 20, 30, 40], 
                 'count': [7, 5, 2, 3]})
lakes.set_index('co tp', inplace=True)

My solution:

area_dict = lakes.set_index("area")["count"].to_dict()

or @punchagan 's solution (which I prefer)

area_dict = dict(zip(lakes.area, lakes.count))

Both should work.

Answer 5

Answering @Jessie Marks question, on how to use this dict(zip(***)) approach if you want to use multiple columns as keys / values, the answer is to zip the zips; eg:

dict(zip(df['key'], zip(df["value col 1"], df_['value col 1'])))

or if you wish to use multiple columns as keys:

dict(zip(zip(df['key 1'], df['key 2']), zip(df["value col 1"], df_['value col 1'])))

this worked for me on pandas v1.1.5 ; python 3.6.13

PS. sorry i do not respond directly under @Jessie Marks question, its new account and I cannot do that yet.

Answer 6

你需要这个

area_dict = lakes.to_dict(orient='records')