fastnml 1.0.5

A simple fast namelist parser

fastnml

A Python library to quickly read Fortran namelists.

The fastnml code only works with a specific subset of the namelist format. It is not nearly as general or robust as f90nml, but it is much faster when reading very large namelists. Also, both codes are tested using multiprocessing to read many namelists in parallel.

Test results

Each test was repeated 10 times using timeit. Reported times are averages.

-----------------------------
test.nml
-----------------------------

f90nml: Read all at once from file (0 threads) :       8.583405899999999 sec
f90nml: Read in chunks (0 threads) :                   4.6838695999999995 sec
f90nml: Read in chunks (1 threads) :                   4.937748499999998 sec
f90nml: Read in chunks (2 threads) :                   2.5980871000000008 sec
f90nml: Read in chunks (3 threads) :                   1.9029447000000026 sec
f90nml: Read in chunks (4 threads) :                   1.5512989000000026 sec
fastnml: Read in chunks (0 threads) :                  0.4889088999999984 sec
fastnml: Read in chunks (1 threads) :                  0.6726308000000003 sec
fastnml: Read in chunks (2 threads) :                  0.49938099999999963 sec
fastnml: Read in chunks (3 threads) :                  0.4068599000000006 sec
fastnml: Read in chunks (4 threads) :                  0.39626249999999885 sec

-----------------------------
test4.nml
-----------------------------

f90nml: Read all at once from file (0 threads) :       33.611139800000004 sec
f90nml: Read in chunks (0 threads) :                   24.9464172 sec
f90nml: Read in chunks (1 threads) :                   22.7366057 sec
f90nml: Read in chunks (2 threads) :                   11.587078000000005 sec
f90nml: Read in chunks (3 threads) :                   8.443905700000016 sec
f90nml: Read in chunks (4 threads) :                   6.226133799999985 sec
fastnml: Read in chunks (0 threads) :                  1.0096473000000117 sec
fastnml: Read in chunks (1 threads) :                  1.3259695000000136 sec
fastnml: Read in chunks (2 threads) :                  1.036898100000002 sec
fastnml: Read in chunks (3 threads) :                  1.159534999999977 sec
fastnml: Read in chunks (4 threads) :                  1.0741505999999958 sec

-----------------------------
test4b.nml
-----------------------------

f90nml: Read all at once from file (0 threads) :       7.980078500000019 sec
f90nml: Read in chunks (0 threads) :                   8.990785700000004 sec
f90nml: Read in chunks (1 threads) :                   9.161885600000005 sec
f90nml: Read in chunks (2 threads) :                   4.726017299999995 sec
f90nml: Read in chunks (3 threads) :                   3.553860500000013 sec
f90nml: Read in chunks (4 threads) :                   2.7503221000000053 sec
fastnml: Read in chunks (0 threads) :                  0.37847529999999097 sec
fastnml: Read in chunks (1 threads) :                  0.677776300000005 sec
fastnml: Read in chunks (2 threads) :                  0.5017527999999913 sec
fastnml: Read in chunks (3 threads) :                  0.5212353000000007 sec
fastnml: Read in chunks (4 threads) :                  0.41918479999998226 sec

-----------------------------
test4c.nml
-----------------------------

f90nml: Read all at once from file (0 threads) :       11.072592100000008 sec
f90nml: Read in chunks (0 threads) :                   40.973017 sec
f90nml: Read in chunks (1 threads) :                   28.69594159999997 sec
f90nml: Read in chunks (2 threads) :                   14.902919899999972 sec
f90nml: Read in chunks (3 threads) :                   10.096066500000006 sec
f90nml: Read in chunks (4 threads) :                   8.136358200000018 sec
fastnml: Read in chunks (0 threads) :                  1.1177955999999654 sec
fastnml: Read in chunks (1 threads) :                  1.526128500000027 sec
fastnml: Read in chunks (2 threads) :                  1.060428600000023 sec
fastnml: Read in chunks (3 threads) :                  0.9990597000000321 sec
fastnml: Read in chunks (4 threads) :                  1.0846950000000106 sec

Dependencies

• f90nml -- the more general library