Example 1: select rows from dataframe pandas
from pandas import DataFrame
boxes = {'Color': ['Green','Green','Green','Blue','Blue','Red','Red','Red'],
'Shape': ['Rectangle','Rectangle','Square','Rectangle','Square','Square','Square','Rectangle'],
'Price': [10,15,5,5,10,15,15,5]
}
df = DataFrame(boxes, columns= ['Color','Shape','Price'])
select_color = df.loc[df['Color'] == 'Green']
print (select_color)
Example 2: pandas index
How to add index to the DataFrame at runtime
df["patient"] = ["patient-" + str( i ) for i in range( max( df.index ) + 1 )]
df.set_index( "patient", inplace=True )
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patient = pandas.Series( ["patient-" + str( i ) for i in range( max( df.index ) + 1 )] )
df.index = patient
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df.index = ["patient-" + str( i ) for i in range( max( df.index ) + 1 )]
Example 3: pandas df by row index
indices = [133, 22, 19, 203, 14, 1]
df_by_indices = df.iloc[indices, :]
Example 4: add an index column in range dataframe
df = df.loc[df.index.repeat(df['a'])]
df['c'] = df.groupby(level=0).cumcount() + 1
df = df.reset_index(drop=True)
print (df)
a b c
0 1 x 1
1 2 y 1
2 2 y 2
3 3 z 1
4 3 z 2
5 3 z 3
Example 5: indexing column in pandas
In [8]: age_sex = titanic[["Age", "Sex"]]
In [9]: age_sex.head()
Out[9]:
Age Sex
0 22.0 male
1 38.0 female
2 26.0 female
3 35.0 female
4 35.0 male
Example 6: indexing column in pandas
In [10]: type(titanic[["Age", "Sex"]])
Out[10]: pandas.core.frame.DataFrame