Example 1: finding the index of an element in a pandas df
In [48]: a
Out[48]:
c1 c2
0 0 1
1 2 3
2 4 5
3 6 7
4 8 9
In [49]: a.c1[a.c1 == 8].index.tolist()
Out[49]: [4]
Example 2: 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 3: 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 )
---------------------------------------------------------------------
patient = pandas.Series( ["patient-" + str( i ) for i in range( max( df.index ) + 1 )] )
df.index = patient
---------------------------------------------------------------------
df.index = ["patient-" + str( i ) for i in range( max( df.index ) + 1 )]
Example 4: df.index
The index (row labels) of the DataFrame.
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