python unhashable type error

Question

Traceback  most recent call last     File   lt pyshell 80 gt    line 1  in  lt module gt      do work     File  C  pythonwork readthefile080410 py   line 14  in do work     populate frequency5 e data    File  C  pythonwork readthefile080410 py   line 157  in populate frequency5     data medications minimum3 data  drug upper    1    File  C  pythonwork readthefile080410 py   line 120  in medications minimum3     counter row 11    1 TypeError  unhashable type   list    I am getting the above error on this line   data medications minimum3 data  drug upper    1     I have also tried drug upper   without brackets   Here is a preview of this function   def medications minimum3 c drug input sample cutoff    return sample cut off for   medications physician   d      counter collections defaultdict int    for row in c      counter row 11    1   for row in c      if counter row 11   gt  sample cutoff        d append row     write file d   pythonwork medications minimum3 csv     return d   Does anyone know what I am doing wrong here   I know that what must be wrong is the way I am calling this function  because I call this function from a different location and it works fine   d medications minimum3 c drug input 50    Thank you very much for your help

User · Answer

counter row 11    1   You don t show what data is  but apparently when you loop through its rows  row 11  is turning out to be a list  Lists are mutable objects which means they cannot be used as dictionary keys  Trying to use row 11  as a key causes the defaultdict to complain that it is a mutable  i e  unhashable  object   The easiest fix is to change row 11  from a list to a tuple  Either by doing  counter tuple row 11       1   or by fixing it in the caller before data is passed to medications minimum3  A tuple simply an immutable list  so it behaves exactly like a list does except you cannot change it once it is created

User · Answer

As Jim Garrison said in the comment  no obvious reason why you d make a one-element list out of drug upper    which implies drug is a string    But that s not your error  as your function medications minimum3   doesn t even use the second argument  something you should fix    TypeError  unhashable type   list  usually means that you are trying to use a list as a hash argument  like for accessing a dictionary   I d look for the error in counter row 11    1 -- are you sure that row 11  is of the right type  Sounds to me it might be a list

User · Answer

File  C  pythonwork readthefile080410 py   line 120  in medications minimum3     counter row 11    1 TypeError  unhashable type   list    row 11  is unhashable   It s a list   That is precisely  and only  what the error message means   You might not like it  but that is the error message     Do this  counter tuple row 11     1   Also  simplify   d    row for row in c if counter tuple row 11    gt  sample cutoff

User · Answer

I don t think converting to a tuple is the right answer  You need go and look at where you are calling the function and make sure that c is a list of list of strings  or whatever you designed this function to work with  For example you might get this error if you passed  c  to the function instead of c

[python] python: unhashable type error

Examples related to python