ValueError: cannot reindex from duplicate axis using isin with pandas

I am trying to make short zipcodes into various files, but I keep getting

ValueError: cannot reindex from duplicate axis

I read other documentation on Stackoverflow but I was not going to figure out why its a duplicate axis.

import csv
import pandas as pd
from pandas import DataFrame as df
fp = '/Users/User/Development/zipcodes/file.csv'
file1 = open(fp, 'rb').read()
df = pd.read_csv(fp, sep=',')

df = df[['VIN', 'Reg Name', 'Reg Address', 'Reg City', 'Reg ST', 'ZIP',
         'ZIP', 'Catagory', 'Phone', 'First Name', 'Last Name', 'Reg NFS',
         'MGVW', 'Make', 'Veh Model','E Mfr', 'Engine Model', 'CY2010',
         'CY2011', 'CY2012', 'CY2013', 'CY2014', 'CY2015', 'Std Cnt', 
        ]]
#reader.head(1)
df.head(1)
zipBlue = [65355, 65350, 65345, 65326, 65335, 64788, 64780, 64777, 64743,
64742, 64739, 64735, 64723, 64722, 64720]

      

        
        
        
      

    

Also contains zipGreen, zipRed, zipYellow, ipLightBlue

but is not included in the example.

def IsInSort():
    blue = df[df.ZIP.isin(zipBlue)]
    green = df[df.ZIP.isin(zipGreen)]
    red = df[df.ZIP.isin(zipRed)]
    yellow = df[df.ZIP.isin(zipYellow)]
    LightBlue = df[df.ZIP.isin(zipLightBlue)]
def SaveSortedZips():
    blue.to_csv('sortedBlue.csv')
    green.to_csv('sortedGreen.csv')
    red.to_csv('sortedRed.csv')
    yellow.to_csv('sortedYellow.csv')
    LightBlue.to_csv('SortedLightBlue.csv')
IsInSort()
SaveSortedZips()

      

        
        
        
      

    

1864 # attempt to reindex along the axis with duplicates 1865
if not self.is_unique and len (indexer): → 1866 raise ValueError ("cannot reindex from duplicate axis") 1867 1868 def reindex (self, target, method = None, level = None , limit = None):

ValueError: cannot reindex from duplicate axis