I want to calculate math operation in a f-string using a variable passed to format method. For example i need something like :
print(f"{{a}} * 3".format(a=2))
This code prints:
2 * 3
But i want the result that's 6. Also i wont use python eval function to evaluate this string.
As stated by PEP 498:
The
str.format()"expression parser" is not suitable for use when implementing f-strings.
While you could do something like:
name = "John"
age = 30
print(f'My name is {{0}} and I am 5 years older than {age - 5}'.format(name))
what you asked for in your original question is not doable.
You can also read this Reddit thread to see why that would probably be a bad idea.
print(f"{a * 3}".format(a=2)). +1You need to put the 3 in curly braces as well:
>>> a = 2
>>> print(f"{a * 3}")
6
>>>
str.format method. Also, you never made it clear you had to use the str.format method. Please state all your requirements in your question before hand next time.
print(f"{a * 3}".format(a=2)) does work but what's the purpose of the f-strings then?print(f"{a * 3}".format(a=2)) raises NameError: name 'a' is not defined.
You can try this.
print((int(f"{{a}}".format(a=2)))*3)
eval (or int or float for ...) functions!
