Save file in .csv file or tab delimited file

One day, I tried to finish a project in which I used some flat file. First, I save the file to .txt tab delimited file. And when I read in the file, there was always an error, like the rows are not of the same length. Then I converted the file to .csv file. There was no more error. Later on, I found, since when it was tab delimited file, some columns were not actually delimited by tab, i.e. two or more columns are collapsed together, and became one column. So for different rows the number of columns are not equal. But when I used the csv file, no such issue, since the commas are always there, and separated the columns.

So maybe the csv files are safer to used than tab delimited file.