How to flash message with variables in Flask

I want to flash a message with a variable in flask. Can anyone tell me how can i do so.
For example:

a = 3
flash("message + A + message continues")

I want to achieve this.

>Solution :

You will need to insert your variable into the string that you give to flash().

There are different ways to achieve this:

a = 3
message = "message {} message continues".format(a)  # Using the format method
message = f"message {a} message continues"  # Using f-strings (Python >= 3.6)
message = "message %d message continues" % (a)  # % Formatting
message = "message " + str(a) + " message continues"  # Concatenation
flash(message)