I want to write a function which prints the items in a list that all contain at least one similar character and the amount of times it appears in each item.
For example if I had the following list:

```
ex = ['bat', 'cat', 'task', 'tank', 'tan']

```

Each item contains the letter 'a' and 't' at least once.

I know I could use

```
for string in ex:
        for letter in string:
            x = string.count("a")
        print(string, "has", x, "a")

    for string in ex:
        for letter in string:
            x = string.count("t")
        print(word, "has", x, "t")

```

How would I do this without specifying the actual characters to search for like above, in case I would like to change the list?