Using readtable with double-quote strings in .csv file

조회 수: 19(최근 30일)
a.tom
a.tom 2015년 2월 17일
답변: Al in St. Louis 2022년 5월 19일
I am trying to read in a .csv file with double-quoted strings (i.e. "asdf") separated by commas. It does not seem that readtable can handle this gracefully when I have a string that contains a comma (i.e. "asdf,asdf"). It sees this as additional columns or something. The .csv file works fine with Excel 2007.
A sample/example file 'runFile.csv' with 3 columns. The top-row is:
"runName","runCount","runVal",
"runName" is an arbitrary string that may contain commas. "runCount", "resultVal" are doubles/integers.
Full sample file:
"runName","runCount","resultVal",
"asdf,asdf,asdf",1,1234,
"asdf,asdf,asdf",2,2345,
"asdf,asdf,asdf",3,3465,
When I run this in R2014b-64b (under Windows 7, 64-bit), I get:
>> T = readtable('runFile.csv')
Error using readtable (line 129)
Cannot interpret data in the file "runFile.csv'. Found 4 variable names but 6 data columns. You may need to specify a different format string, delimiter, or number of header lines.
I tried to use the extra parameter 'Format' with '%s%f%f' or something, but could not get it to work. I tried variations like '"%s"%f%f or something to no success.
I see that the release notes for R2014b shows some note about writetable now supporting double-quote strings using the 'QuoteStrings' parameter, but I could not find much more about this, or whether it is supported in readtable.
Thanks, Alex
  댓글 수: 1
Al in St. Louis
Al in St. Louis 2022년 5월 19일
This is still a problem with R2021a

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답변(2개)

Kuang-Chieh Yen
Kuang-Chieh Yen 2016년 9월 10일
편집: Kuang-Chieh Yen 2016년 9월 10일
The data format, %q, can be used to read data with double-quotes. So, you should replace %f and by %q. Maybe it works well. Moreover, I also recommend to run "datastore", for example
% get the information of yourdata
ds = datastore('yourdata.csv');
% import yourdata into T
T = read(ds);
HOPE IT USEFUL !

Al in St. Louis
Al in St. Louis 2022년 5월 19일
Switch from MATLAB to Python. Pandas has no problem with a properly constructed CSV file. It's sad that readtable can't parse something this simple.

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