在python for csv中添加新行以打印列输出

我对python相当陌生，正在尝试确定实现这一点的最佳方法。我有以下代码。

import csv
from collections import defaultdict
columns = defaultdict(list)

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
    for (k,v) in row.items():
        columns[k].append(v)

print(columns['Created'])
print(columns['Person'])
print(columns['Comment'])

Created,UnwantedData,Person,Bogus,Comment
4-15-17,test,Chad,w,There is an update
4-16-17,for,Marlon,x,There is no update
4-17-17,this ,Kevin,y,I have reviewed the files
4-18-17,issue,Dan,z,I hate this place.

['4-15-17', '4-16-17', '4-17-17', '4-18-17']
['Chad', 'Marlon', 'Kevin', 'Dan']]
['There is an update ', 'There is no update', 'I have reviewed the files ', 'I hate this place. ']

4-15-17   
Chad   
There is an update     

4-16-17
Marlon
There is no update

4-17-17
Kevin
I have reviewed the files

4-18-17 
Dan
I hate this place.

我正在对下面的CSV文件输出运行它。

import csv
from collections import defaultdict
columns = defaultdict(list)

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
    for (k,v) in row.items():
        columns[k].append(v)

print(columns['Created'])
print(columns['Person'])
print(columns['Comment'])

Created,UnwantedData,Person,Bogus,Comment
4-15-17,test,Chad,w,There is an update
4-16-17,for,Marlon,x,There is no update
4-17-17,this ,Kevin,y,I have reviewed the files
4-18-17,issue,Dan,z,I hate this place.

['4-15-17', '4-16-17', '4-17-17', '4-18-17']
['Chad', 'Marlon', 'Kevin', 'Dan']]
['There is an update ', 'There is no update', 'I have reviewed the files ', 'I hate this place. ']

4-15-17   
Chad   
There is an update     

4-16-17
Marlon
There is no update

4-17-17
Kevin
I have reviewed the files

4-18-17 
Dan
I hate this place.

我只想打印创建的、人物和评论部分，但我得到的是下面的内容。

import csv
from collections import defaultdict
columns = defaultdict(list)

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
    for (k,v) in row.items():
        columns[k].append(v)

print(columns['Created'])
print(columns['Person'])
print(columns['Comment'])

Created,UnwantedData,Person,Bogus,Comment
4-15-17,test,Chad,w,There is an update
4-16-17,for,Marlon,x,There is no update
4-17-17,this ,Kevin,y,I have reviewed the files
4-18-17,issue,Dan,z,I hate this place.

['4-15-17', '4-16-17', '4-17-17', '4-18-17']
['Chad', 'Marlon', 'Kevin', 'Dan']]
['There is an update ', 'There is no update', 'I have reviewed the files ', 'I hate this place. ']

4-15-17   
Chad   
There is an update     

4-16-17
Marlon
There is no update

4-17-17
Kevin
I have reviewed the files

4-18-17 
Dan
I hate this place.

我试图通过在每次打印输出之间添加新行，使输出看起来像这样。

import csv
from collections import defaultdict
columns = defaultdict(list)

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
    for (k,v) in row.items():
        columns[k].append(v)

print(columns['Created'])
print(columns['Person'])
print(columns['Comment'])

Created,UnwantedData,Person,Bogus,Comment
4-15-17,test,Chad,w,There is an update
4-16-17,for,Marlon,x,There is no update
4-17-17,this ,Kevin,y,I have reviewed the files
4-18-17,issue,Dan,z,I hate this place.

['4-15-17', '4-16-17', '4-17-17', '4-18-17']
['Chad', 'Marlon', 'Kevin', 'Dan']]
['There is an update ', 'There is no update', 'I have reviewed the files ', 'I hate this place. ']

4-15-17   
Chad   
There is an update     

4-16-17
Marlon
There is no update

4-17-17
Kevin
I have reviewed the files

4-18-17 
Dan
I hate this place.

---

当您打印

列['Created']

时，您将打印创建列中存储的所有内容。相反，您只需要遍历列中的每个项

import csv
from collections import defaultdict
columns = defaultdict(list)

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
        for (k, v) in row.items():
            columns[k].append(v)

for i in xrange(len(columns['Created'])):
    print(columns['Created'][i])
    print(columns['Person'][i])
    print(columns['Comment'][i] + "\n")

---

“\n”将导致在注释部分后打印新行。

我是否可以建议一种替代方法，您只需创建一个带有

dict

的新条目列表，只需将其筛选为只包含所需的键

import csv
wanted = ('Created', 'Person', 'Comment')

with open('test.csv') as f:
    rdr = csv.DictReader(f)

    result = []
    for row in rdr:
        result.append({k: v for k, v in row.items() if k in wanted})

for r in result:
    print(r['Created'])
    print(r['Person'])
    print(r['Comment'])
    print('')

如果您希望使用现有代码，只需使用

zip

重新加入每个列表中的项目即可

import csv
from collections import defaultdict
columns = defaultdict(list)

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row in reader:
        for k, v in row.items():
            columns[k].append(v)

params = [columns['Created'], columns['Person'], columns['Comment']]
for cre, pers, cmt in zip(*params):
    print(cre)
    print(pers)
    print(cmt)
    print('')

---

可以在一次迭代中获得结果。这样可以节省时间

import csv
from collections import defaultdict

with open('test.csv') as f:
    reader = csv.DictReader(f)
    for row_dict in reader:
        print "%s\n%s\n\n" % (row_dict['Created'], row_dict["Person"], row_dict['Comment'])