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'''
LESSION 4
- Adding/deleting columns
- Index operations
'''
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# Import libraries
import pandas as pd
import sys
print('Python version ' + sys.version)
print('Pandas version: ' + pd.__version__)
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# Our small data set
d = [0,1,2,3,4,5,6,7,8,9]
# Create dataframe
df = pd.DataFrame(d)
df
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# Lets change the name of the column
df.columns = ['Rev']
df
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# Lets add a column
df['NewCol'] = 5
df
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# Lets modify our new column
df['NewCol'] = df['NewCol'] + 1
df
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# We can delete columns
del df['NewCol']
df
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# Lets add a couple of columns
df['test'] = 3
df['col'] = df['Rev']
df
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# If we wanted, we could change the name of the index
i = ['a','b','c','d','e','f','g','h','i','j']
df.index = i
df
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df.loc['a']
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# df.loc[inclusive:inclusive]
df.loc['a':'d']
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# df.iloc[inclusive:exclusive]
# Note: .iloc is strictly integer position based. It is available from [version 0.11.0] (http://pandas.pydata.org/pandas-docs/stable/whatsnew.html#v0-11-0-april-22-2013)
df.iloc[0:3]
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df['Rev']
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df[['Rev', 'test']]
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# df.ix[rows,columns]
df.ix[0:3,'Rev']
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df.ix[5:,'col']
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df.ix[:3,['col', 'test']]
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# Select top N number of records (default = 5)
df.head()
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# Select bottom N number of records (default = 5)
df.tail()
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