问题
When I tried to read a csv file using data.table:fread(fn, sep='\t', header=T), it gives an "Unbalanced " observed on this line" error. The data has 3 integer variables and 1 string variable. The strings in the csv file are not enclosed with ", and yes there are some lines that contains " within the string variable and the " characters are not in pairs.
I am wondering is it possible to let fread just ignore the unpaired " in the variable and continue reading data? Thanks.
Here is the sample data(just one record)
N_ID VISIT_DATE REQ_URL REQType
175931 2013-3-8 23:40:30 http://aaa.com/rest/api2.do?api=getSetMobileSession&data={"imei":"60893ZTE-CN13cd","appkey":"android_client","content":"Z0JiRA0qPFtWM3BYVltmcx5MWF9ZS0YLdW1ydXoqPycuJS8idXdlY3R0TGBtU 1
回答1:
UPDATE: Now implemented in v1.8.11
From NEWS :
fread now accepts quotes (both ' and ") in the middle of fields, whether the field starts with " or not, rather than the 'unbalanced quotes' error, #2694. Thanks to baidao for reporting. It was known and documented at the top of ?fread (text now removed). If a field starts with " it must end with " (necessary if the field separator itself is in the field contents). Embedded quotes can be in column names too. Newlines (\n) still can't be in quoted fields or quoted column names, yet.
Yes as @agstudy said, embedded quotes are a known documented problem not yet implemented since fread is new. Strictly speaking, I suppose these ones aren't embedded because the string in your example doesn't start with a quote, though.
Anyway, I've filed this as a bug report so it doesn't get forgotten. To be done in the next release. Thanks for highlighting.
#2694 : Strings including quotes but not starting with quote in fread
来源：https://stackoverflow.com/questions/16094025/data-tablefread-and-unbalanced