Python正則表達式：查找所有以“ {”開頭和以“}”結尾的行

Question

我正在通過套接字，一堆JSON字符串接收數據。 但是，我接收到一定數量的字節，因此有時我的JSON字符串的最后一個被截斷了。 我通常會得到以下信息：

{"pitch":-30.778193,"yaw":-124.63285,"roll":-8.977466}
{"pitch":-30.856342,"yaw":-124.57556,"roll":-7.7220345}
{"pitch":-31.574106,"yaw":-124.65623,"roll":-7.911794}
{"pitch":-30.479567,"yaw":-124.24301,"roll":-8.730827}
{"pitch":-29.30239,"yaw":-123.97949,"roll":-8.134723}
{"pitch":-29.84712,"yaw":-124.584465,"roll":-8.588374}
{"pitch":-31.072054,"yaw":-124.707466,"roll":-8.877062}
{"pitch":-31.493435,"yaw":-124.75457,"roll":-9.019922}
{"pitch":-29.591925,"yaw":-124.960815,"roll":-9.379437}
{"pitch":-29.37105,"yaw":-125.14427,"roll":-9.642341}
{"pitch":-29.483717,"yaw":-125.16528,"roll":-9.687177}
{"pitch":-30.903332,"yaw":-124.603935,"roll":-9.423098}
{"pitch":-30.211857,"yaw":-124.471664,"roll":-9.116135}
{"pitch":-30.837414,"yaw":-125.18984,"roll":-9.824204}
{"pitch":-30.526165,"yaw":-124.85788,"roll":-9.158611}
{"pitch":-30.333513,"yaw":-123.68705,"roll":-7.9481263}
{"pitch":-30.903502,"yaw":-123.78847,"roll":-8.209373}
{"pitch":-31.194769,"yaw":-124.79708,"roll":-8.709783}
{"pitch":-30.816765,"yaw":-125

使用Python，我想創建前18個完整{ data... }字符串的字符串數組。

這是我嘗試過的： cleanData = re.search('{.*}', data)但似乎這只是給我第一個{ data... }條目。 如何獲得完整的{}集的完整字符串數組？

Answer 1

要獲得全部，可以使用re.finditer或re.findall 。

>>> re.findall(r'{.*}', s)
['{"pitch":-30.778193,"yaw":-124.63285,"roll":-8.977466}', '{"pitch":-30.856342,"yaw":-124.57556,"roll":-7.7220345}', '{"pitch":-31.574106,"yaw":-124.65623,"roll":-7.911794}', '{"pitch":-30.479567,"yaw":-124.24301,"roll":-8.730827}', '{"pitch":-29.30239,"yaw":-123.97949,"roll":-8.134723}', '{"pitch":-29.84712,"yaw":-124.584465,"roll":-8.588374}', '{"pitch":-31.072054,"yaw":-124.707466,"roll":-8.877062}', '{"pitch":-31.493435,"yaw":-124.75457,"roll":-9.019922}', '{"pitch":-29.591925,"yaw":-124.960815,"roll":-9.379437}', '{"pitch":-29.37105,"yaw":-125.14427,"roll":-9.642341}', '{"pitch":-29.483717,"yaw":-125.16528,"roll":-9.687177}', '{"pitch":-30.903332,"yaw":-124.603935,"roll":-9.423098}', '{"pitch":-30.211857,"yaw":-124.471664,"roll":-9.116135}', '{"pitch":-30.837414,"yaw":-125.18984,"roll":-9.824204}', '{"pitch":-30.526165,"yaw":-124.85788,"roll":-9.158611}', '{"pitch":-30.333513,"yaw":-123.68705,"roll":-7.9481263}', '{"pitch":-30.903502,"yaw":-123.78847,"roll":-8.209373}', '{"pitch":-31.194769,"yaw":-124.79708,"roll":-8.709783}']
>>> 

要么

>>> [x.group() for x in re.finditer(r'{.*}', s)]
['{"pitch":-30.778193,"yaw":-124.63285,"roll":-8.977466}', '{"pitch":-30.856342,"yaw":-124.57556,"roll":-7.7220345}', '{"pitch":-31.574106,"yaw":-124.65623,"roll":-7.911794}', '{"pitch":-30.479567,"yaw":-124.24301,"roll":-8.730827}', '{"pitch":-29.30239,"yaw":-123.97949,"roll":-8.134723}', '{"pitch":-29.84712,"yaw":-124.584465,"roll":-8.588374}', '{"pitch":-31.072054,"yaw":-124.707466,"roll":-8.877062}', '{"pitch":-31.493435,"yaw":-124.75457,"roll":-9.019922}', '{"pitch":-29.591925,"yaw":-124.960815,"roll":-9.379437}', '{"pitch":-29.37105,"yaw":-125.14427,"roll":-9.642341}', '{"pitch":-29.483717,"yaw":-125.16528,"roll":-9.687177}', '{"pitch":-30.903332,"yaw":-124.603935,"roll":-9.423098}', '{"pitch":-30.211857,"yaw":-124.471664,"roll":-9.116135}', '{"pitch":-30.837414,"yaw":-125.18984,"roll":-9.824204}', '{"pitch":-30.526165,"yaw":-124.85788,"roll":-9.158611}', '{"pitch":-30.333513,"yaw":-123.68705,"roll":-7.9481263}', '{"pitch":-30.903502,"yaw":-123.78847,"roll":-8.209373}', '{"pitch":-31.194769,"yaw":-124.79708,"roll":-8.709783}']
>>> 

Answer 2

您需要re.findall() （或re.finditer ）

>>> import re
>>> for r in re.findall(r'{.*}', data)[:18]:
    print r


{"pitch":-30.778193,"yaw":-124.63285,"roll":-8.977466}
{"pitch":-30.856342,"yaw":-124.57556,"roll":-7.7220345}
{"pitch":-31.574106,"yaw":-124.65623,"roll":-7.911794}
{"pitch":-30.479567,"yaw":-124.24301,"roll":-8.730827}
{"pitch":-29.30239,"yaw":-123.97949,"roll":-8.134723}
{"pitch":-29.84712,"yaw":-124.584465,"roll":-8.588374}
{"pitch":-31.072054,"yaw":-124.707466,"roll":-8.877062}
{"pitch":-31.493435,"yaw":-124.75457,"roll":-9.019922}
{"pitch":-29.591925,"yaw":-124.960815,"roll":-9.379437}
{"pitch":-29.37105,"yaw":-125.14427,"roll":-9.642341}
{"pitch":-29.483717,"yaw":-125.16528,"roll":-9.687177}
{"pitch":-30.903332,"yaw":-124.603935,"roll":-9.423098}
{"pitch":-30.211857,"yaw":-124.471664,"roll":-9.116135}
{"pitch":-30.837414,"yaw":-125.18984,"roll":-9.824204}
{"pitch":-30.526165,"yaw":-124.85788,"roll":-9.158611}
{"pitch":-30.333513,"yaw":-123.68705,"roll":-7.9481263}
{"pitch":-30.903502,"yaw":-123.78847,"roll":-8.209373}
{"pitch":-31.194769,"yaw":-124.79708,"roll":-8.709783}

Answer 3

無需任何正則表達式就可以提取以特定字符開頭和結尾的行，在遍歷文件中的str.endswith使用str.startswith和str.endswith方法：

results = []
with open(filepath, 'r') as f:
    for line in f:
        if line.startswith('{') and line.rstrip('\n').endswith('}'):
            results.append(line.rstrip('\n'))

注意.rstrip('\\n')之前使用.endswith ，以確保最終的換行符不與干擾}檢查字符串的結尾。