Simpler way to create dictionary of separate variables?

Question

I would like to be able to get the name of a variable as a string but I don\'t know if Python has that much introspection capabilities. Something like:

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Answer 1

Most objects don't have a __name__ attribute. (Classes, functions, and modules do; any more builtin types that have one?)

What else would you expect for print(my_var.__name__) other than print("my_var")? Can you simply use the string directly?

You could "slice" a dict:

def dict_slice(D, keys, default=None):
  return dict((k, D.get(k, default)) for k in keys)

print dict_slice(locals(), ["foo", "bar"])
# or use set literal syntax if you have a recent enough version:
print dict_slice(locals(), {"foo", "bar"})

Alternatively:

throw = object()  # sentinel
def dict_slice(D, keys, default=throw):
  def get(k):
    v = D.get(k, throw)
    if v is not throw:
      return v
    if default is throw:
      raise KeyError(k)
    return default
  return dict((k, get(k)) for k in keys)