df.rename(columns) returns KeyError: ..values.. not found in axis"-CodePudding

I have imported a file with no column names (they have defaulted to 0, 1, 2 ...). I want to rename them to Var1, Var2 .. respectively. Have searched the documentation and various sites.

I'm sure this is a simple problem, but please guide me :)

pd.DataFrame.info(thyroidX)

<class 'pandas.core.frame.DataFrame'>
RangeIndex: 3772 entries, 0 to 3771
Data columns (total 6 columns):
 #   Column  Non-Null Count  Dtype  
---  ------  --------------  -----  
 0   0       3772 non-null   float64
 1   1       3772 non-null   float64
 2   2       3772 non-null   float64
 3   3       3772 non-null   float64
 4   4       3772 non-null   float64
 5   5       3772 non-null   float64
dtypes: float64(6)
memory usage: 176.9 KB


thyroidX.rename(columns = {"0" : "Var1", "1" : "Var2", "2" : "Var3", "3" : "Var4", "4" : "Var5",\
                           "5" : "Var6"}, inplace = True, errors = "raise")

---------------------------------------------------------------      
KeyError                                  Traceback (most recent call last)
Input In [39], in <cell line: 6>()
      1 # Rename column names before merge 
      2 # based on https://stackabuse.com/how-to-rename-pandas-dataframe-column-in-python/
      3 # x vars
      4 #thyroidX.rename(columns = {"0" : "Var1", "1" : "Var2", "2" : "Var3", "3" : "Var4", "4" : "Var5",\
      5 #                           "5" : "Var6"}, inplace = True, errors = "raise")
----> 6 thyroidX.rename({"0" : "Var1", "1" : "Var2", "2" : "Var3", "3" : "Var4", "4" : "Var5",\
      7                            "5" : "Var6"}, axis = 1, inplace = True, errors = "raise")

.....                     
KeyError: "['0', '1', '2', '3', '4', '5'] not found in axis"

CodePudding user response：

Try this:

thyroidX.rename(columns = {0 : "Var1", 1 : "Var2", 2 : Var3, 3 : Var4, 4 : "Var5", 5 : "Var6"}, inplace = True, errors = "raise")

or, if all columns are numeric

thyroidX.columns = ["Var1",  "Var2", "Var3", "Var4", "Var5",  "Var6"]

CodePudding user response：

You need to specify axis=1 to apply to columns