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pythontypesfrozenset

python TypeError: frozenset expected at most 1 arguments, got 4

I'm getting this error when trying to make a frozen set:

class Transcriber:

    DNA_BASES = frozenset('A','T','G','C')
...

And this is the Traceback:

~/python/project5$ python wp_proj5.py 
Traceback (most recent call last):
  File "wp_proj5.py", line 5, in <module>
    class Transcriber:
  File "wp_proj5.py", line 7, in Transcriber
    DNA_BASES = frozenset('A','T','G','C')
TypeError: frozenset expected at most 1 arguments, got 4

What is wrong here? Can't I initialize a frozenset with more than one string?

Solution

  • You need to pass an iterable like a list:

    frozenset(['A','T','G','C'])

    You can read about it here: http://docs.python.org/2/library/stdtypes.html#frozenset