问题
I'm trying to write data to a csv file. The data is in a confusing format and I cannot change it. This is how the data dictionary looks like. How do i write this data in a csv file?
[{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
}]
I tried using the code below however, using this code only writes the field names in the csv file and not the values.
import csv
with open('peak.csv', 'w') as csvFile:
fields = ['box ', 'confidence', 'keypoints' ]
writer = csv.DictWriter(csvFile, fieldnames=fields)
writer.writeheader()
writer.writerows(result)
print("writing completed")
csvFile.close()
This is the result I'm getting. Results
回答1:
Couple of quick things. The function you posted has an extra space in 'box' entry of the fields list, and in python the with keyword will automatically close a file for you. No need to do it explicitly.
I have tested this on my machine, running Python 3.6. I included a duplicate in the list because I assume your data has more than a single output list? If not it shouldn't make a difference.
Are you sure the following code doesn't work?
import csv
data = [{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
},
{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
}
]
# Write to csv
with open('data.csv', 'w') as f:
fields = ['box', 'confidence', 'keypoints']
w = csv.DictWriter(f, fieldnames=fields)
w.writeheader()
w.writerows(data)
# Append to existing csv
with open('data.csv', 'a') as f:
fields = ['box', 'confidence', 'keypoints']
w = csv.DictWriter(f, fieldnames=fields)
w.writerows(data)
With the output:
box,confidence,keypoints
"[277, 90, 48, 63]",0.99,"{'left_eye': (291, 117), 'right_eye': (314, 114), 'nose': (303, 131), 'mouth_left': (296, 143), 'mouth_right': (313, 141)}"
"[277, 90, 48, 63]",0.99,"{'left_eye': (291, 117), 'right_eye': (314, 114), 'nose': (303, 131), 'mouth_left': (296, 143), 'mouth_right': (313, 141)}"
What the output looks like in LibreCalc
If you want the keys of keypoints in their own columns:
import csv
data = [{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
},
{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
}
]
with open('data2.csv', 'w') as f:
# get a list of the keys in the values of 'keypoints' key
kps = data[0].get('keypoints').keys()
# make the list for the fieldnames, * just expands a list to its components
fields = ['box', 'confidence', *kps]
w = csv.DictWriter(f, fieldnames=fields)
w.writeheader()
out_dict = {}
# Loop over however many data dictionaries are in the list data
for data_dict in data:
# Loop over keys and values in the dictionary
for k, v in data_dict.items():
if k != 'keypoints':
out_dict.update({k: v})
elif k == 'keypoints':
# Loop over the keys that correspond to 'keypoints' key
for k2, v2 in data_dict['keypoints'].items():
out_dict.update({k2: v2})
# Write the created out dictionary to the file
w.writerow(out_dict)
# Appending to an already existing csv
with open('data2.csv', 'a') as f:
kps = data[0].get('keypoints').keys()
# make the list for the fieldnames, * just expands a list to its components
fields = ['box', 'confidence', *kps]
w = csv.DictWriter(f, fieldnames=fields)
out_dict = {}
# Loop over however many data dictionaries are in the list data
for data_dict in data:
# Loop over keys and values in the dictionary
for k, v in data_dict.items():
if k != 'keypoints':
out_dict.update({k: v})
elif k == 'keypoints':
# Loop over the keys that correspond to 'keypoints' key
for k2, v2 in data_dict['keypoints'].items():
out_dict.update({k2: v2})
# Write the created out dictionary to the file
w.writerow(out_dict)
With this output:
box,confidence,left_eye,right_eye,nose,mouth_left,mouth_right
"[277, 90, 48, 63]",0.99,"(291, 117)","(314, 114)","(303, 131)","(296, 143)","(313, 141)"
"[277, 90, 48, 63]",0.99,"(291, 117)","(314, 114)","(303, 131)","(296, 143)","(313, 141)"
flattened output in LibreCalc
This second function is effectively the same as flattening a json as one of the other answers mentioned, just without a dependency.
回答2:
Assuming you want dict data of keypoints in csv
import csv
results = [{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
}]
with open('peak.csv', 'w') as csv_file:
writer = csv.writer(csv_file)
writer.writerow(result[0].keys())
for resultDict in results:
writer.writerow(resultDict.values())
csv_file.close()
CSV file content:
box, confidence, keypoints
"[277, 90, 48, 63]", 0.99, "{'left_eye': (291, 117), 'mouth_left': (296, 143), 'nose': (303, 131), 'mouth_right': (313, 141), 'right_eye': (314, 114)}"
回答3:
Just extract the dic from the list and write its keys and values with items():
with open('peak.csv', 'w') as csv_file:
writer = csv.writer(csv_file)
for key, value in list[0].items():
writer.writerow([key, value])
回答4:
If you don't mind using a package for it, you can install the flatten_json package from pypi, usage found here: https://github.com/amirziai/flatten#usage
If so, then your code becomes something like this:
import csv
import flatten_json
result = [
{
'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
}
]
flattened_result = flatten_json.flatten(result[0])
with open('peak.csv', 'w') as csvFile:
fields = list(flattened_result.keys())
writer = csv.DictWriter(csvFile, fieldnames=fields)
writer.writeheader()
writer.writerow(flattened_result)
print("writing completed")
Output looks like:
box_0,box_1,box_2,box_3,confidence,keypoints_left_eye,keypoints_right_eye,keypoints_nose,keypoints_mouth_left,keypoints_mouth_right
277,90,48,63,0.99,"(291, 117)","(314, 114)","(303, 131)","(296, 143)","(313, 141)"
回答5:
This might work for you. Though I'm not sure how you want to represent the key value pairs in 'keypoints'
import csv
myDict = [{'box': [277, 90, 48, 63],
'confidence': 0.99,
'keypoints': {
'left_eye': (291, 117),
'right_eye': (314, 114),
'nose': (303, 131),
'mouth_left': (296, 143),
'mouth_right': (313, 141)}
}]
with open('peak.csv', 'w') as csv_file:
writer = csv.writer(csv_file)
writer.writerow(myDict[0].keys())
for item in myDict:
writer.writerow(item.values())
print("writing completed")
csv_file.close()
Output looks like:
box,confidence,keypoints
"[277, 90, 48, 63]",0.99,"{'left_eye': (291, 117), 'mouth_left': (296, 143), 'nose': (303, 131), 'mouth_right': (313, 141), 'right_eye': (314, 114)}"
来源：https://stackoverflow.com/questions/55447758/how-do-i-write-this-piece-of-data-to-a-csv-file