import pandas
data = pandas.read_csv('Twitter-sentiment-self-drive-DFE.csv', 
                          encoding = "ISO-8859-1")

head(py$data)

##    _unit_id _golden _unit_state _trusted_judgments _last_judgment_at
## 1 724227031    TRUE      golden                236               NaN
## 2 724227032    TRUE      golden                231               NaN
## 3 724227033    TRUE      golden                233               NaN
## 4 724227034    TRUE      golden                240               NaN
## 5 724227035    TRUE      golden                240               NaN
## 6 724227036    TRUE      golden                241               NaN
##   sentiment sentiment:confidence our_id sentiment_gold
## 1         5               0.7579  10001           5\n4
## 2         5               0.8775  10002           5\n4
## 3         2               0.6805  10003           2\n1
## 4         2               0.8820  10004           2\n1
## 5         3               1.0000  10005              3
## 6         3               1.0000  10006              3
##                                                        sentiment_gold_reason
## 1                 Author is excited about the development of the technology.
## 2          Author is excited that driverless cars will benefit the disabled.
## 3 The author is skeptical of the safety and reliability of a driverless car.
## 4                            The author is skeptical of the project's value.
## 5             Author is making an observation without expressing an opinion.
## 6                 Author is asking a question without expressing an opinion.
##                                                                                                                     text
## 1                                    Two places I'd invest all my money if I could: 3D printing and Self-driving cars!!!
## 2                        Awesome! Google driverless cars will help the blind travel more often; https://t.co/QWuXR0FrBpv
## 3   If Google maps can't keep up with road construction, how am I supposed to trust a driverless car to get around here?
## 4 Autonomous cars seem way overhyped given the technology challenges; pilotless planes seem much more doable and needed.
## 5                                               Just saw Google self-driving car on I-34. It was painted green and blue.
## 6                                                        Will driverless cars eventually replace taxi drivers in cities?

print(data.columns)

## Index([u'_unit_id', u'_golden', u'_unit_state', u'_trusted_judgments',
##        u'_last_judgment_at', u'sentiment', u'sentiment:confidence', u'our_id',
##        u'sentiment_gold', u'sentiment_gold_reason', u'text'],
##       dtype='object')

colnames(py$data)

##  [1] "_unit_id"              "_golden"              
##  [3] "_unit_state"           "_trusted_judgments"   
##  [5] "_last_judgment_at"     "sentiment"            
##  [7] "sentiment:confidence"  "our_id"               
##  [9] "sentiment_gold"        "sentiment_gold_reason"
## [11] "text"

print(data['sentiment'].head())

## 0    5
## 1    5
## 2    2
## 3    2
## 4    3
## Name: sentiment, dtype: object

head(py$data$sentiment)

## [1] "5" "5" "2" "2" "3" "3"

Can also write like this:

head(py$data[,"sentiment"])

## [1] "5" "5" "2" "2" "3" "3"