Passing a dictionary to a function as keyword parameters

Question

I d like to call a function in python using a dictionary   Here is some code   d   dict param  test    def f param       print param   f d    This prints   param    test   but I d like it to just print test   I d like it to work similarly for more parameters   d   dict p1 1  p2 2  def f2 p1  p2       print p1  p2  f2 d    Is this possible

User · Accepted Answer

Figured it out for myself in the end  It is simple  I was just missing the    operator to unpack the dictionary  So my example becomes   d   dict p1 1  p2 2  def f2 p1 p2       print p1  p2 f2   d

User · Answer

In 1   def myfunc a 1  b 2   In 2      print a  b   In 3   mydict     a   100   b   200   In 4   myfunc   mydict  100 200   A few extra details that might be helpful to know  questions I had after reading this and went and tested     The function can have parameters that are not included in the dictionary You can not override a parameter that is already in the dictionary The dictionary can not have parameters that aren t in the function    Examples   Number 1  The function can have parameters that are not included in the dictionary  In 5   mydict     a   100  In 6   myfunc   mydict  100 2   Number 2  You can not override a parameter that is already in the dictionary  In 7   mydict     a   100   b   200  In 8   myfunc a 3    mydict   TypeError  myfunc   got multiple values for keyword argument  a    Number 3  The dictionary can not have parameters that aren t in the function   In 9    mydict     a   100   b   200   c   300  In 10   myfunc   mydict   TypeError  myfunc   got an unexpected keyword argument  c      As requested in comments  a solution to Number 3 is to filter the dictionary based on the keyword arguments available in the function   In 11   import inspect In 12   mydict     a   100   b   200   c   300  In 13   filtered mydict    k  v for k  v in mydict items   if k in  p name for p in inspect signature myfunc  parameters values     In 14   myfunc   filtered mydict  100 200   Another option is to accept  and ignore  additional kwargs in your function   In 15   def myfunc2 a None    kwargs   In 16      print a   In 17   mydict     a   100   b   200   c   300   In 18   myfunc2   mydict  100     Notice further than you can use positional arguments and lists or tuples in effectively the same way as kwargs  here s a more advanced example incorporating both positional and keyword args   In 19   def myfunc3 a   posargs  b 2    kwargs   In 20      print a  b  In 21      print posargs  In 22      print kwargs   In 23   mylist    10  20  30  In 24   mydict     b   200   c   300   In 25   myfunc3  mylist    mydict  10 200  20  30    c   300

User · Answer

In python  this is called  unpacking   and you can find a bit about it in the tutorial  The documentation of it sucks  I agree  especially because of how fantasically useful it is

User · Answer

Here ya go - works just any other iterable   d     param     test    def f dictionary       for key in dictionary          print key  f d

User · Answer

In python  this is called  unpacking   and you can find a bit about it in the tutorial  The documentation of it sucks  I agree  especially because of how fantasically useful it is

User · Answer

In python  this is called  unpacking   and you can find a bit about it in the tutorial  The documentation of it sucks  I agree  especially because of how fantasically useful it is

User · Answer

In 1   def myfunc a 1  b 2   In 2      print a  b   In 3   mydict     a   100   b   200   In 4   myfunc   mydict  100 200   A few extra details that might be helpful to know  questions I had after reading this and went and tested     The function can have parameters that are not included in the dictionary You can not override a parameter that is already in the dictionary The dictionary can not have parameters that aren t in the function    Examples   Number 1  The function can have parameters that are not included in the dictionary  In 5   mydict     a   100  In 6   myfunc   mydict  100 2   Number 2  You can not override a parameter that is already in the dictionary  In 7   mydict     a   100   b   200  In 8   myfunc a 3    mydict   TypeError  myfunc   got multiple values for keyword argument  a    Number 3  The dictionary can not have parameters that aren t in the function   In 9    mydict     a   100   b   200   c   300  In 10   myfunc   mydict   TypeError  myfunc   got an unexpected keyword argument  c      As requested in comments  a solution to Number 3 is to filter the dictionary based on the keyword arguments available in the function   In 11   import inspect In 12   mydict     a   100   b   200   c   300  In 13   filtered mydict    k  v for k  v in mydict items   if k in  p name for p in inspect signature myfunc  parameters values     In 14   myfunc   filtered mydict  100 200   Another option is to accept  and ignore  additional kwargs in your function   In 15   def myfunc2 a None    kwargs   In 16      print a   In 17   mydict     a   100   b   200   c   300   In 18   myfunc2   mydict  100     Notice further than you can use positional arguments and lists or tuples in effectively the same way as kwargs  here s a more advanced example incorporating both positional and keyword args   In 19   def myfunc3 a   posargs  b 2    kwargs   In 20      print a  b  In 21      print posargs  In 22      print kwargs   In 23   mylist    10  20  30  In 24   mydict     b   200   c   300   In 25   myfunc3  mylist    mydict  10 200  20  30    c   300

User · Answer

Here ya go - works just any other iterable   d     param     test    def f dictionary       for key in dictionary          print key  f d

User · Answer

In python  this is called  unpacking   and you can find a bit about it in the tutorial  The documentation of it sucks  I agree  especially because of how fantasically useful it is

User · Answer

Here ya go - works just any other iterable   d     param     test    def f dictionary       for key in dictionary          print key  f d

User · Answer

Here ya go - works just any other iterable   d     param     test    def f dictionary       for key in dictionary          print key  f d

[python] Passing a dictionary to a function as keyword parameters

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