Python：字典列表 - 使用键作为标题和行是值(朴素的方式)

Question

我目前的任务是从字典列表中创建一个CSV文件，其中标题是dic键，行是dic值

Ex。

dictionary_list = [{ 'key1': 'value1', 'key2: 'value2', 'key3': 'value3'}, {'key1': 'value4', 'key2: 'value5', 'key3': 'value6'}]

输出将是CSV文件：

key1,key2,key3
value1,value2,value3
value4,value5,value6

我们不允许使用dictwritter/csv/panda，而且必须以天真的方式使用

我目前已经收集了密钥，但正在努力拆分值，这样它就不会在同一行打印出所有值，而是在新行中写入第二个字典值：

我的获取值代码：

v = [x for y in dictionary_list for x in y.values()]
finalV = ','.join(str(x) for x in v)

我当前的文件输出：

key1,key2,key3
value1,value2,value3,value4,value5,value6

Answer 1

您可以这样做。首先写下列表中任意dict的键。

然后，对列表进行迭代，并逐行写入值。

dictionary_list = [{ 'key1': 'value1', 'key2': 'value2', 'key3': 'value3'},
{'key1': 'value4', 'key2': 'value5', 'key3': 'value6'}]
f = open("test.csv", "a")
f.write(','.join(list(dictionary_list[0].keys()))) #write headers
f.write('n')

for i in dictionary_list:
f.write(','.join(list(i.values()))) #write values
f.write('n')
f.close()

我的输出是

key1,   key2,   key3
value1, value2, value3
value4, value5, value6

Answer 2

你可以这样做，

lst = [{'key1': 'value1', 'key2': 'value2', 'key3': 'value3'},
{'key1': 'value4', 'key2': 'value5', 'key3': 'value6'}]
with open("test.csv", "w") as f:
# write header
f.write(f"{','.join(lst[0].keys())}n")
# write values
for item in lst:
f.write(f"{','.join(item.values())}n")

Answer 3

# if you know for a fact that all dictionaries have identical keys
keys = ",".join(dictionary_list[0].keys()) 
values = "n".join([",".join(v for v in d.values()) for d in dictionary_list])
final = keys + "n" + values
# then dump string to csv

此时，final是一个逗号分隔的字符串：

'key1,key2,key3nvalue1,value2,value3nvalue4,value5,value6'

然后你可以把它写到磁盘上：

with open("some_file.csv", 'w') as f:
f.write(final)

Answer 4

以下是使用operator.itemgetter:的解决方案

from operator import itemgetter
dictionary_list = [
{'key1': 'value1', 'key2': 'value2', 'key3': 'value3'},
{'key1': 'value4', 'key2': 'value5', 'key3': 'value6'},
]
# Get the keys out of the first dictionary
keys = list(dictionary_list[0].keys())
# Create an itemgetter using the keys
x = itemgetter(*keys)
# Use a context-manager to create a file to write against
with open("output.csv", "w") as csv:
# Write the headers using the keys from the first dictionary
csv.write(",".join(keys) + "n")
# Loop over each dictionary, and use the itemgetter to get the values in the same order.
for i in dictionary_list:
csv.write(",".join(x(i))+ "n")

输出是一个名为"的文件；输出.csv"；，其中包含：

key1,key2,key3
value1,value2,value3
value4,value5,value6

Answer 5

您可以将其用于您的案例。这可能是工作。

f = open("demofile.csv", "w")
key = ",".join([*dictionary_list[0]])+'n'
f.write(key)
for dictionary in dictionary_list:
values = ','.join([val for val in dictionary.values()])+'n'
f.write(values)
f.close()