Here is an experiment you can do to demonstrate the power of a good oak cane
place a broom across two blocks with about 3 ft. between and swing down hard with the cane it will snap the broom like breaking someones arm.

I work for a living so everyday carry for me is a mini maglight..my Buck folder and my shop keys on a heavy snap ring..I carry my cane incase my hip bothers me..I dont always carry my derranger ..but always the Maglight and knife and now my cane

A full water bottle works ok as a club. Once empty though, not so much. But it can still serve as a distraction to dogs. I like the sports drink bottles that fit in a bicycle water bottle cage, since having to chuck one is no big loss. Cyclists with loose dogs along their route may be familiar with this one.

A sock with something heavy like coins or batteries is pretty effective too. But carrying it around full may be frowned upon in some places. A small drawstring bag with a long cord upon it can serve the same purpose though and may not look as odd as carrying a sock around.

What you know is also an unassuming weapon. Understanding a few martial-art based defenses which are based more on speed and technique (exploiting pressure and leverage points) than strength may be good enough to disable an attacker. Such techniques may be considered generic and easy enough to counter, but if you don't look like a security guard or thug - somebody coming at you may assume you don't have such defenses and can still be taken down with them.

I carry a 5.1/2 foot two piece walking stick that i made.

Fiber glass shaft with solid brass ends and Farrel type connector like used on fishing pole.
The brass ends have replaceable rubber corks in recesses for good ground contact on slick floors.
It comes apart into two nice sticks and the brass end give it weight where needed

I was trained in Arnis(Eskrima)stick fighting back in my navy days in the Philippines.(early 1970s)
I am now a disabled veteran and i have been through every type security checkpoint airline, bus,VA hospitals, and train, and Have never been stopped or questioned about my walking stick.

A 10$ good quality metal pen. Just as good as any kubotan against pressure points and you cannot be charged for carrying a weapon.

My mind, nobody ever expects me to use it as a weapon.

And if that fails then my fists, legs and my entire body, become's my weapon.

And if that fails then anything and everything around me, becomes my weapon.

You see everything can be a weapon in the right hands, at the right time, in the right place.

However my favorite weapons are the Japanese sword because its shiny and some are a real piece of art. I like to just look at and admire there craftsmanship and beauty, and off-course guns, the bigger the better.

I took a composite golf club, cut off the head, then i slide a sharpened 30'' stainless steel rod with a handle down in it..the rubber grip holds it securely. simple. cheap. effective.

oh yeah-i have two heavy ludwig drumsticks that i can clip together and use as num-chuks.