String formatting: % vs. .format vs. f-string literal

There are various string formatting methods:

• Python <2.6: "Hello %s" % name
• Python 2.6+: "Hello {}".format(name)   (uses str.format)
• Python 3.6+: f"{name}"   (uses f-strings)

Which is better, and for what situations?

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1. The following methods have the same outcome, so what is the difference?

   name = "Alice"
   
   "Hello %s" % name
   "Hello {0}".format(name)
   f"Hello {name}"
   
   # Using named arguments:
   "Hello %(kwarg)s" % {'kwarg': name}
   "Hello {kwarg}".format(kwarg=name)
   f"Hello {name}"
   

2. When does string formatting run, and how do I avoid a runtime performance penalty?

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_{If you are trying to close a duplicate question that is just looking for a way to format a string, please use How do I put a variable’s value inside a string?.}