I have a log in which I am trying to parse errors found in a log file into a csv file. The log looks like this:

[2019-Apr-01 13:00:02.343][Test][Info][2929:12][Writing.To.Log] Reading ABC.
[2019-Apr-01 13:00:03.343][Test][Alarm][8192:12][Test.In.Progress] Severity: Error0, Description: 'Information = ABC:1:ABC Value went over upper limit, Value = 93.0625 C, Error0UCL = 30 C.', ContactInfo: 555-555-5555
[2019-Apr-01 13:00:04.343][Test][Info][2929:12][Writing.To.Log] Reading DEF.
[2019-Apr-01 13:00:05.353][Test][Alarm][8193:12][Test.In.Progress] Severity: Error0, Description: 'Information = DEF:1:DEF Value went over upper limit, Value = 93.0625 C, Error0UCL = 30 C.', ContactInfo: 555-555-5555

So far I have the code like this:

pattern = r'\[([^]] )\]'
timePattern=r"\d{4}......."
ErrorLevelPattern= r'Error(\S ?)'
instrumentPattern= r'Information ={1}(.*?):{1}' #group1
valuePattern=r'Value ={1}(.*?),{1}'
descriptionPattern=r"('[^'] ')"

with open('Parsed.csv', 'w') as out_file:
    with open('Log.txt', 'r') as in_file:
        writer = csv.writer(out_file)
        writer.writerow(['Date', 'Time', 'ErrorLevel', 'InstrumentType', 'Value', 'ContactInfo', 'Description'])
        for line in in_file:
            if "Severity: Error" in line:
                print(re.findall(instrumentPattern,line))

I am attempting to create the output file as follows:

CodePudding user response：

It seems there is some confusion between quantifiers and groups. You should probably read more on the subject. You can simplify all your individual patterns and combine them in a global one. You can match descriptionPattern separately to keep the code simple:

datePattern=r"(\d{4}-[a-zA-Z]{3}-\d{2})"
timePattern=r"(\d{2}:\d{2}:\d{2}\.\d{3})"
ErrorLevelPattern= r'Error(\S ),'
instrumentPattern= r'Information = (.*?):'
valuePattern=r'Value = (\S )'
contact_pattern = r'ContactInfo: (\S )'

full_pattern = re.compile(rf"{datePattern} {timePattern}.*?{ErrorLevelPattern}.*?{instrumentPattern}.*?{valuePattern}.*?{contact_pattern}")

descriptionPattern=r"'([^'] )'"

with open('Parsed.csv', 'w', newline='') as out_file:
    with open('Log.txt', 'r') as in_file:
        writer = csv.writer(out_file)
        writer.writerow(['Date', 'Time', 'ErrorLevel', 'InstrumentType', 'Value', 'ContactInfo', 'Description'])
        for line in in_file:
            if "Severity: Error" in line:
                fields = list(*re.findall(full_pattern, line))
                fields.append(re.search(descriptionPattern,line).group(1))
                writer.writerow(fields)

Output:

Date,Time,ErrorLevel,InstrumentType,Value,ContactInfo,Description
2019-Apr-01,13:00:03.343,0,ABC,93.0625,555-555-5555,"Information = ABC:1:ABC Value went over upper limit, Value = 93.0625 C, Error0UCL = 30 C."
2019-Apr-01,13:00:05.353,0,DEF,93.0625,555-555-5555,"Information = DEF:1:DEF Value went over upper limit, Value = 93.0625 C, Error0UCL = 30 C."