select lines in python

[amrita at iisermohali.ac.in]

Dear all,

Can anyone tell me that suppose i have a file having content like:

    _Atom_name
      _Atom_type
      _Chem_shift_value
      _Chem_shift_value_error
      _Chem_shift_ambiguity_code
     1     1   PHE       H     H      8.49     0.02     1
     2     1   PHE       HA    H      4.60     0.02     1
     3     1   PHE       CA    C     57.83      0.3     1
     4     2   LEU       H     H      8.23     0.02     1
     5     2   LEU       HA    H      4.25     0.02     1
     6     2   LEU       HB2   H      1.54     0.02     1
     7     3   ASP       H     H      8.10     0.02     1
     8     3   ASP       HA    H      4.52     0.02     1
     9     3   ASP       HB2   H      2.65     0.02     1
stop


now what i want that instead of copying all the lines it will just write
the information about PHE and ASP then how i acn do that using python
programming.Kindly tell me the command for that.

Thanks,
Amrita Kumari
Research Fellow
IISER Mohali
Chandigarh
INDIA