Looking up Pandas dataFrame

Question

I have created a data frame by reading a text file. I am interested in knowing if few values exist in a particular column and if they do, I want to print the entire row.

This is my input file(analyte_map.txt):

Analyte_id    mass    Intensity   
A34579        101.2    786788
B12345        99.2     878787
B943470       103.89   986443
C12345        11.2      101

This is my code:

import pandas as pd
map_file="analyte_map.txt"
array=['A34579','B943470','D583730']
analyte_df=pd.read_table(map_file,sep="\t")
for value in array:
    if analyte_df.lookup([value],['Analyte_id']):
        print '%s\t%s'%(analyte_df['mass'],analyte_df['Intensity'])

Answer 1

You can use boolean indexing with isin :

array=['A34579','B943470','D583730']
print (df[df.analyte_id.isin(array)])
  analyte_id    mass  Intensity
0     A34579  101.20     786788
2    B943470  103.89     986443

Also if need only some columns use ix :

array=['A34579','B943470','D583730']
print (df.ix[df.analyte_id.isin(array), ['mass','Intensity']])
     mass  Intensity
0  101.20     786788
2  103.89     986443

Answer 2

using .query() method:

In [9]: look_up=['A34579','B943470','D583730']

In [10]: df.query('Analyte_id in @look_up')
Out[10]:
  Analyte_id    mass  Intensity
0     A34579  101.20     786788
2    B943470  103.89     986443

In [11]: df.query('Analyte_id in @look_up')[['mass','Intensity']]
Out[11]:
     mass  Intensity
0  101.20     786788
2  103.89     986443