1 #!/usr/bin/env python3

2 #

3 import sys

4 import os

5 import time

6 import datetime

7 import netCDF4 as nc

8 import numpy as np

9 

10 if len(sys.argv) != 3:

11  print('Usage:')

12  callseq = sys.argv[0] + ' file ' + 'attr-file'

13  print(callseq)

14  print('\nThis script modifies attributes in a netCDF file')

15  print('\tfile:\t\tsource file to modify')

16  print('\tattr-file:\tfile containig attribue=value pairs to modify\n')

17  print('\tTo delete an attribute, set the value to a blank string\n')

18  print('\tAttributes listed in the attr-file but not existing in the netCDF file\n\twill be added')

19  print('\tFor group attributes, prepend the attribute name with the group,\n\tdelineated with a "/", e.g.:')

20  print('\t\tnavigation_data/mycoolattribute=awesomeness')

21  sys.exit(1)

22 

23 inFile = sys.argv[1]

24 attrFile = sys.argv[2]

25 rootgrp = nc.Dataset(inFile, 'a')

26 

27 # generate string to update the history

28 processtime = datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%dT%H:%M:%S')

29 if 'history' in rootgrp.ncattrs():

30  history = nc.Dataset.getncattr(rootgrp,'history').rstrip() + '\n'+'['+processtime+'] '+os.path.basename(sys.argv[0])+ ' ' + sys.argv[1] + ' ' + sys.argv[2]

31 else:

32  history = '['+processtime+'] ' + os.path.basename(sys.argv[0]) + ' ' + sys.argv[1] + ' ' + sys.argv[2]

33 

34 attrs = open(attrFile,'r')

35 

36 for attr in attrs:

37  attrName,attrValue = attr.split('=')

38  attrValue = attrValue.rstrip()

39  group = rootgrp

40  try:

41  parts = attrName.split('/')

42  if len(parts) > 1:

43  attrName = parts.pop()

44  attrGroup = '/'.join(parts).strip()

45  group = rootgrp.createGroup(attrGroup)

46  except:

47  pass

48 

49  # Check to see if the attribute exists,

50  # if it does, delete it

51  try:

52  attrValueExisting = nc.Dataset.getncattr(group,attrName)

53  nc.Dataset.delncattr(group,attrName)

54  except:

55  pass

56 

57  # if starts with a quote it is a string

58  try:

59  if len(attrValue):

60  if attrValue.startswith('"'):

61  attrValue = attrValue.strip('"').encode('ascii')

62  nc.Dataset.setncattr(group,attrName,attrValue)

63  else:

64  # if has a comma it is an array

65  if "," in attrValue:

66  if attrValue.startswith('['):

67  attrValue = attrValue.lstrip('[').rstrip(']')

68  partsStr = attrValue.split(',')

69  if '.' in attrValue:

70  parts = np.array(partsStr).astype(np.dtype('f4'))

71  else:

72  parts = np.array(partsStr).astype(np.dtype('i4'))

73  nc.Dataset.setncattr(group,attrName,parts)

74 

75  else:

76  if '.' in attrValue:

77  nc.Dataset.setncattr(group,attrName,np.array(attrValue).astype(np.dtype('f4')))

78  else:

79  nc.Dataset.setncattr(group,attrName,np.array(attrValue).astype(np.dtype('i4')))

80  except Exception as e:

81  sys.exit("Whoops! Something went seriously wrong:\n"+ str(e))

82 

83 # update the history

84 nc.Dataset.setncattr(rootgrp,'history', history)

85 

86 

87 rootgrp.close()