Python：将字典打印到csv，每个键值都换行

Question

I have the following data

{'index': [1, 2, 3], 'similar': [[0, 2], [1, 2], [2, 1]], 'markets': [['A', 'C'], ['B', 'C'], ['A', 'B']]}

and I want to print it to a csv file as following:

index   similar  markets
1       [0,2]   ['A','C']
2       [1,2]   ['B','C']
3       [2,1]   ['A','B']

currently my code is as following:

with open('mycsvfile.csv', 'wb') as f:  # Just use 'w' mode in 3.x
    w = csv.DictWriter(f, a.keys())
    w.writeheader()
    w.writerow(a)

and it prints:

 index               similair                       markets
[1, 2, 3]   [[0, 2], [1, 2], [2, 1]]    [['A', 'C'], ['B', 'C'], ['A', 'B']]

Answer 1

import csv

a = {'index': [1, 2, 3], 'similar': [[0, 2], [1, 2], [2, 1]], 'markets': [['A', 'C'], ['B', 'C'], ['A', 'B']]}
keys = ['index', 'similar', 'markets']

with open('mycsvfile.csv', 'wb') as f:  # Just use 'w' mode in 3.x
    w = csv.writer(f)
    w.writerow(keys)
    w.writerows(zip(*[a[key] for key in keys]))

CSV file:

index,similar,markets
1,"[0, 2]","['A', 'C']"
2,"[1, 2]","['B', 'C']"
3,"[2, 1]","['A', 'B']"

Answer 2

you can use the pandas library:

import pandas as pd

x = {'index': [1, 2, 3], 'similar': [[0, 2], [1, 2], [2, 1]], 'markets': [['A', 'C'], ['B', 'C'], ['A', 'B']]}

x = pd.DataFrame(x)
x.to_csv('mycsvfile.csv', index = False)

the csv will be:

index,markets,similar
1,"['A', 'C']","[0, 2]"
2,"['B', 'C']","[1, 2]"
3,"['A', 'B']","[2, 1]"