3.1. Main reader interface
The class Reader
has been designed to selectively extract data
from a mzML file and to expose the data as a python object.
Necessary information are read in and stored in a fast
accessible format.
The reader itself is an iterator, thus looping over all spectra
follows the classical pythonian syntax.
Additionally one can random access spectra by their nativeID
if the file if not truncated by a conversion Program.
Note
The class Writer
is still in development.
- class pymzml.run.Reader(path_or_file, MS_precisions=None, obo_version=None, build_index_from_scratch=False, skip_chromatogram=True, index_regex=None, **kwargs)[source]
Initialize Reader object for a given mzML file.
- Parameters
path (str) – path to the mzml file to parse.
- Keyword Arguments
MS_precisions (dict) –
measured precisions for the different MS levels. e.g.:
{ 1 : 5e-6, 2 : 20e-6 }
obo_version (str, optional) – obo version number as string. If not specified the version will be extracted from the mzML file
Note
Setting the precision for MS1 and MSn spectra has changed in version 1.2. However, the old syntax as kwargs is still compatible ( e.g. ‘MS1_Precision=5e-6’).
- __getitem__(identifier)[source]
Access spectrum with native id ‘identifier’.
- Parameters
identifier (str or int) – last number in the id tag of the spectrum element
- Returns
spectrum/chromatogram object with native id ‘identifier’
- Return type
spectrum (Spectrum or Chromatogram)
- property file_class
Return file object in use.
- get_chromatogram_count()[source]
Number of chromatograms in file.
- Returns
Number of chromatograms in file.
- Return type
chromatogram count (int)