Number of characters in the column name of a DataFrame

Question

I'm consuming an API and some column names are too big for mysql database.

How to ignore field in dataframe?

I was trying this:

import pandas as pd
import numpy as np

lst =['Java', 'Python', 'C', 'C++','JavaScript', 'Swift', 'Go'] 

df = pd.DataFrame(lst)
limit = 7

for column in df.columns:
   if (pd.to_numeric(df[column].str.len())) > limit:
        df -= df[column]
        print (df)

result:

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

My preference is to delete the column that is longer than my database supports.

But I tried slice to change the name and it didn't work either.

I appreciate any help

Answer 1

As I mentioned in my comment, when you do df = pd.DataFrame(lst) you are saying to create a dataframe with a single column where the rows are populated by your single-dimension list. So iterating through columns of the dataframe isn't doing anything as there is only a single column

That being said, this is an advantage as you can use a set based approach to answer your question:

import pandas as pd
import numpy as np

lst =['Java', 'Python', 'C', 'C++','JavaScript', 'Swift', 'Go'] 

df = pd.DataFrame(lst)

limit = 7
print(df[df[0].str.len() > limit])

That will spit out a dataframe with a single column and a single row containing "Javascript" the only value that is over your character length limit. If you wanted to keep the values that are under the limit just change that > to <=.