Pandas df.plot() KeyError Thrown

Question

BIG EDIT: This error will not throw if I remove index_col = 1 from the read_csv function. Leaving this question up because I am curious why this happens.

I have the following CSV:

Agency  Division                   Expenditures ($000,000)
NYPD    OPERATIONS                 3331
NYPD    EXECUTIVE MANAGEMENT       489.4
NYPD    SCHOOL SAFETY              279.6
NYPD    ADMINISTRATION-PERSONNEL   263.9

When I plot this with:

data.plot(x='Division',y='Expenditures ($000,000)')

I am thrown:

KeyError: 'Division'

I am confused because my index is named 'Division' so why would I be thrown this error? Using data.plot(kind='bar') gives me a reasonable plot, but I am having an issue calling this column by its key.

Full code below:

import matplotlib.pyplot as plt
import numpy as np
import pandas as pd

NYPD_data = "D:/CSVs/NYPD_Spending.csv"
data = pd.read_csv(NYPD_data, index_col = 1)

plt.figure(1, figsize=(10,10))
plt.xlabel('NYPD Division')
data.plot(x='Division', y='Expenditures ($000,000)')

plt.show()

Answer 1

data = {'Agency': {0: 'NYPD', 1: 'NYPD', 2: 'NYPD', 3: 'NYPD'},
        'Division': {0: 'OPERATIONS',
                     1: 'EXECUTIVE MANAGEMENT',
                     2: 'SCHOOL SAFETY',
                     3: 'ADMINISTRATION-PERSONNEL'},
        'Expenditures ($000,000)': {0: 3331.0, 1: 489.4, 2: 279.6, 3: 263.9}}

df = pd.DataFrame.from_dict(data)

plt.figure(figsize=(10, 10))
plt.plot(df['Division'], df['Expenditures ($000,000)'])
plt.xticks(rotation='30')
plt.xlabel('NYPD Division')
plt.show()

Produces Plot:

df.plot('Division', 'Expenditures ($000,000)')
df.plot(x='Division', y='Expenditures ($000,000)')

Does not work:

df.plot(x=df['Division'], y=['Expenditures ($000,000)'])

This doesn't work because the source is already specified by df.plot . x & y should be x : label or position, default None and y : label, position or list of label, positions, default None respectively. So the issue is sending parameters to the method in an incorrect form. pandas.DataFrame.plot

DataFrame Plotting API

In the case of:

df = pd.read_csv('Book1.csv', index_col=1)

df = 
                          Agency    Expenditures ($000,000)
Division        
OPERATIONS                  NYPD                     3331.0
EXECUTIVE MANAGEMENT        NYPD                      489.4
SCHOOL SAFETY               NYPD                      279.6
ADMINISTRATION-PERSONNEL    NYPD                      263.9

Note that Division is now the index and no longer a column so using x = 'Division' will not work.

df.plot()