CODEWITHSUNDEEP
python
Lee
Lee

Reputation: 57

Name Error: name 'x' is not defined when working with function

I have 3 dataframes that I'm working with that has the same column names and that I'm working on merging them. The first column is for the dataframes I want the same. The rest of the columns are years, and I wanted to add a letter to each of years to distinguish between the dataframes. I was able to do this manually without any issues. But when I tried defining a function, I get the following error

NameError: name 'x' is not defined.

This is my initial attempt without defining a function. dfyears is the dataframe I'm trying to change the columns names with. The first column 'City_State', I want to keep the same, and the rest I want to add a letter behind depending on the dataframe. 

dfyearlist = (dfyears.columns[1:].values.tolist())
dfcols = [(dfyears.columns[0])]
for i in dfyearlist:
    dfcols.append(i + 'r')
dfyears.columns = dfcols

Here's the first 3 lines of my output:

        City_State        2010r        2011r        2012r        2013r  \
0     New York, NY  1771.666667  1753.384615  1803.615385  1955.384615   
1  Los Angeles, CA  2190.333333  2185.076923  2185.000000  2242.692308   
2      Houston, TX  1198.666667  1195.538462  1197.846154  1252.692308   

         2014r        2015r        2016r        2017r        2018r  
0  2124.000000  2271.230769  2331.846154  2337.384615  2295.846154  
1  2331.384615  2522.692308  2687.000000  2798.307692  2883.153846  
2  1322.076923  1411.461538  1439.461538  1423.615385  1432.923077

But when I tried defining a function:

def changecolumnnames(s, x):
    templist = [s.columns[1:].values.tolist()]
    returnlist = [(s.columns[0])]
    for i in templist:
        returnlist.append(i + str(x))
    s.columns = returnlist 

zillrentyears = changecolumnnames(zillrentyears, r)

I get:

NameError: name 'r' is not defined.

Not sure what I'm doing wrong here?

Upvotes: 0

Views: 2463

Answers (2)

Clarity
Clarity

Reputation: 10873

r is a string and you're trying to pass it as a variable.

You need to change your function to hangecolumnnames(zillrentyears, "r") and then inside the function you can call returnlist.append(i + x) without using str.

Upvotes: 1

Mike
Mike

Reputation: 4255

x is not defined outside of changecolumnnames

You provide r as an input to changecolumnnames. r is your x outside of changecolumnnames

Upvotes: 0

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