how to populate array with multiple rows from csv file using python pandas

I am importing a CSV file using pandas,

CSV Column header - Year, Model, Trim, Result

The values coming in from the csv file are as follows -

Year  |  Model  | Trim  | Result

2012  | Camry   | SR5   | 1
2014  | Tacoma  | SR5   | 1
2014  | Camry   | XLE   | 0
etc..

There are 2500+ rows in the data set containing over 200 unique models.

All Values are then converted to numerical values for analysis purposes.

Here the inputs are the first 3 columns of the csv file and the output is the fourth result column

Here is my script:

import pandas as pd
inmport numpy as np

c1 = []
c2 = []
c3 = []
input = []
output = []

# read in the csv file containing 4 columns
df = pd.read_csv('success.csv')
df.convert_objects(convert_numeric=True)
df.fillna(0, inplace=True)

# convert string values to numerical values
def handle_non_numerical_data(df):
    columns = df.columns.values

    for column in columns:
        text_digit_vals = {}
        def convert_to_int(val):
            return text_digit_vals[val]
        if df[column].dtype != np.int64 and df[column].dtype != np.float64:
            column_contents = df[column].values.tolist()
            unique_elements = set(column_contents)
            x = 0
            for unique in unique_elements:
                if unique not in text_digit_vals:
                    text_digit_vals[unique] = x
                    x+=1

            df[column] = list(map(convert_to_int, df[column]))

    return df

df = handle_non_numerical_data(df)

# extract each column to insert into input array later
c1.append(df['Year'])
c2.append(df['Model'])
c3.append(df['Trim'])

#create input array containg the first 3 rows of the csv file
input = np.stack_column(c1,c2,c3)
output.append(df['Result'])

This works fine except append only excepts 1 value, would I use extend as that seems it would attach it to the end of the array?

UPDATE

Essentially all of this works great, my problem is creating the input array, I would like the array to consist of 3 columns - Year, Model, Trim.

input = ([['Year'], ['Model'], ['Trim']],[['Year'], ['Model'], ['Trim']]...)

I can only seem to add one value on top of the other rather than having them sequence..

What I get now -

input = ([['Year'], ['Year'], ['Year']].., [['Model'], ['Model'], ['Model']]..[['Trim'], ['Trim'], ['Trim']]...)