将字典转换为熊猫数据框

Question

I'm trying to convert a dictionary that only has 1 record to a pandas dataframe. I've used the following code from other solutions:

d =  {'id': 'CS2_056', 'cost': 2, 'name': 'Tap'}

pd.DataFrame(d.items(), columns=['id', 'cost','name'])

But I get the following error:

PandasError: DataFrame constructor not properly called!

Answer 1

You dict has only one record use list:

import pandas as pd
d =  {'id': 'CS2_056', 'cost': 2, 'name': 'Tap'}
df = pd.DataFrame([d], columns=d.keys())
print df

Output:

   id  cost name
0  CS2_056     2  Tap

Answer 2

Might be you are using python3. in python3 we have list there

pd.DataFrame(list(d.items()), columns=['id', 'cost','name'])

Answer 3

An alternative way to create a dataframe with a single row from a dictionary is by creating an empty dataframe first and then append ing to it:

import pandas as pd 
d =  {'id': 'CS2_056', 'cost': 2, 'name': 'Tap'}
df = pd.DataFrame().append(d, ignore_index=True)
print(df)

   cost       id name
0   2.0  CS2_056  Tap

Note that this method is significantly slower than @Serenity 's solution so definitely do not choose this method if you are concerned about performance. But having options is always nice.

Answer 4

Easy command, just make sure you enclose your dictionary in square brackets.

d =  {'id': 'CS2_056', 'cost': 2, 'name': 'Tap'}

df = pd.DataFrame([d])
df

Answer 5

While this question does have a duplicate ( Python Dictionary to Pandas Dataframe ), I believe there's a simplier answer than those provided there.

Convert the values to lists:

d = {'id': ['CS2_056'], 'cost': [2], 'name': ['Tap']}

then simply:

df = pd.DataFrame(d)
print(df)
#     cost       id name
#  0     2  CS2_056  Tap

Keep in mind that if columns order matter you'd still need to explicitly provide columns to DataFrame :

df = pd.DataFrame(d, columns=['id', 'cost', 'name'])
print(df)
#          id  cost name
#  0  CS2_056     2  Tap

Answer 6

Passing an index parameter to the DataFrame constructor works in python 3.

import pandas as pd

d =  {'id': 'CS2_056', 'cost': 2, 'name': 'Tap'}
df = pd.DataFrame(d, index=[0])
print(df)

# Output:
#           id  cost name
#   0  CS2_056     2  Tap