import pandas as pd
import numpy as np

datafilepath="/tmp/data.csv"
colnames="tstamp, spend, budget, impression"

#A date parsing function to feed to read_csv
#Expects string in the format YYYY-MM-dd HH:MM:SS TZ
#Though it doesnt return a timezone aware datetime
def dateparser(datestr):
    dt = datetime.datetime.strptime(datestr,'%Y-%m-%d %H:%M:%S %Z')
    return dt

#Dataframe read_csv
df = pd.read_csv(datafilepath, names=colnames, header=0,date_parser=dateparser, parse_dates=['tstamp'])
df.head()

#Add a column with no values
df['new_column'] = np.nan

#Append all data from one data frame to other
df.append(anotherDataFrame)

#Check and return all rows with boolean for blank columns
#checks if the column 'spend' is null
df[pd.isnull(df['spend']) == True]

#Iterate on rows of dataframe
for index, row in df.iterrows():
    print "[rownum=%s] Time: %s " % (index, row('tstamp'))


#Drop a column
df = df.drop(['spend', axis=1)