The above story is an old, old urban myth that has been doing the rounds for years. My brother told me it at least 10 years ago. There are many variations with different types of shops, even named stores, and sometimes it's a changing room or toilet rather than a grocery cart. Its always something that happened to someone else and was told by a third party. And anyway, a moment's thought reveals a massive flaw. Just because the handbag owner had gone out how would a thief be sure the house was empty?

Obviously watch your possessions carefully and be alert for scams, but don't fall for these stories.

The below is from an article (snopes) about this exact article/scam that was written in 2019.

“This "scam" seemingly hearkens back to the days of landlines, when one could often tie information gleaned from a driver's license (i.e., full name and address) to a phone number through the use of a phone directory or directory assistance. But no similar mechanism exists for now-ubiquitous cellphones. (Possibly one could use the internet to quickly match up a name and address with a phone number, but the odds aren't good.)

Moreover, this scheme relies on the out-of-date notion that if a woman is away from home in the middle of the day, her residence will then necessarily be unoccupied (because, of course, the man of the house will be out working somewhere, and the kids will be in school). But a variety of different domestic scenarios are common these days that would place other people at home in the middle of the day: a woman might be living with roommates or parents or adult children; some 40 per cent of Americans work mostly during nonstandard times and are therefore home during the daytime; working at home is becoming increasingly common, etc.”

https://www.snopes.com/fact-check/purse-in-the-grocery-cart-scam/

No. I keep flour, sugar, rice, salt, cereal, etc. in clear Oxo containers in the pantry.