从包含 Python 中特殊字符的 CSV 单元格中提取字符串

Question

我正在编写一个 Python 程序来从 .CSV 文件列中的每个单元格中提取特定值，然后 使所有提取的值新列。

示例列单元格：（这实际上是一小部分，真正的单元格包含更多数据）

AudioStreams":[{"JitterInterArrival":10,"JitterInterArrivalMax":24,"PacketLossRate":0.01353227,"PacketLossRateMax":0.09027778,"BurstDensity":null,"BurstDuration":null,"BurstGapDensity":null,"BurstGapDuration":null,"BandwidthEst":25245423,"RoundTrip":520,"RoundTripMax":11099,"PacketUtilization":2843,"RatioConcealedSamplesAvg":0.02746676,"ConcealedRatioMax":0.01598402,"PayloadDescription":"SIREN","AudioSampleRate":16000,"AudioFECUsed":true,"SendListenMOS":null,"OverallAvgNetworkMOS":3.487248,"DegradationAvg":0.2727518,"DegradationMax":0.2727518,"NetworkJitterAvg":253.0633,"NetworkJitterMax":1149.659,"JitterBufferSizeAvg":220,"JitterBufferSizeMax":1211,"PossibleDataMissing":false,"StreamDirection":"FROM-to-

我要提取的一个值是 "JitterInterArrival": 和 ,"JitterInterArrivalMax" 之间的数字 10 。但是由于每个单元格都包含相对较长的字符串和周围的特殊字符（例如“”），因此 opener=re.escape(r"***") 和 closer=re.escape(r"***") 将不起作用。

有谁知道更好的解决方案吗？非常感谢！

Answer 1

IIUC，您有一个 json 字符串并希望从其属性中获取值。所以，给定

s = '''
{"AudioStreams":[{"JitterInterArrival":10,"JitterInterArrivalMax":24,"PacketLossRate":0.01353227,"PacketLossRateMax":0.09027778,"BurstDensity":null,
                  "BurstDuration":null,"BurstGapDensity":null,"BurstGapDuration":null,"BandwidthEst":25245423,"RoundTrip":520,"RoundTripMax":11099,"PacketUtilization":2843,"RatioConcealedSamplesAvg":0.02746676,"ConcealedRatioMax":0.01598402,"PayloadDescription":"SIREN","AudioSampleRate":16000,"AudioFECUsed":true,"SendListenMOS":null,"OverallAvgNetworkMOS":3.487248,"DegradationAvg":0.2727518,
                  "DegradationMax":0.2727518,"NetworkJitterAvg":253.0633,
                  "NetworkJitterMax":1149.659,"JitterBufferSizeAvg":220,"JitterBufferSizeMax":1211,
                  "PossibleDataMissing":false}]}
'''

你可以做到

import json
>>> data = json.loads(s)
>>> ji = data['AudioStreams'][0]['JitterInterArrival']
10

在数据框场景中，如果您有一列 col 字符串，例如上述内容，例如

df = pd.DataFrame({"col": [s]})

您可以使用 transform 传递 json.loads 作为参数

df.col.transform(json.loads)

获取 Series 字典。然后，您可以像上面那样操作这些字典或访问数据。

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