CODEWITHSUNDEEP
pythondictionary
Linda
Linda

Reputation: 307

Replacing empty value with "None" in a python dictionary

I have a Python dictionary that I generated from an arcgis shapefile. The dictionary has key = FID (point ID) : value = either nothing or "HH". The dictionary looks like this:

Cluster_dict = {0: [u' '], 1: [u'HH'], 2: [u'HH'], 3: [u' '], 4: [u' '], 5: [u' '], 6: [u' '], 7: [u' '], 8: [u' '], 9: [u' '], 10: [u' '], 11: [u'HH'], 12: [u'HH'], 13: [u'HH'], 14: [u'HH'], 15: [u' '], 16: [u' '], 17: [u' '], 18: [u' '], 19: [u' '], 20: [u' '], 21: [u' '], 22: [u' '], 23: [u'HH'], 24: [u'HH'], 25: [u' '], 26: [u' '], 27: [u' '], 28: [u' ']....}

The extra characters of the value [u' '] and [u'HH'] show up after I created the dictionary from the arcgis shapefile with the following code: 

arcpy.ClustersOutliers_stats('input_file', "GRID_CODE", 'output_file',  "INVERSE_DISTANCE", "EUCLIDEAN_DISTANCE", "NONE", "", "")
Cluster_dict = {}
sc = arcpy.SearchCursor('output_file')
for row in sc:
    Cluster_dict[row.FID] = [row.COType]

print Cluster_dict

I'm trying to use this dictionary to append to a nested list of each point's 8 (or less) neighbors using the following code:

clusterList = []
for clist in Neighbors_List:
    row = []
    for ccode in clist:
        row.append(Cluster_dict[ccode])
    clusterList.append(row)
 print clusterList

But when it gets to row.append(Cluster_dict[ccode]), I get a key error '0'. I'm thinking this is because there is no value for key 0, but I'm not sure about this. When I used the following code to replace all the [u' '] with "None", the dictionary doesn't replace the empty values. I'm using the following code to try and replace [u' '].

for k, v in Cluster_dict.iteritems():
    if v is [u' ']:       #I've also tried '[u' ']'
        Cluster_dict[k] = 'None'

print Cluster_dict

Any help would be appreciated. Would it be easier to strip [u' '] out of all the values in the dictionary? If so, can someone show me how to strip unwanted characters out of a dictionary?

Thanks very much for any help.

Upvotes: 2

Views: 4383

Answers (3)

Ignacio Vazquez-Abrams
Ignacio Vazquez-Abrams

Reputation: 798636

It doesn't do what you want, use == instead.

Also, dict.get()

Also, '0' does not equal 0

Upvotes: 2

nmichaels
nmichaels

Reputation: 50941

Other people have told you what's wrong with using is when you mean ==, but you can skip that whole loop by adding some code earlier:

for row in sc:
    Cluster_dict[row.FID] = [row.COType] if row.COType != u' ' else None

Upvotes: 2

g.d.d.c
g.d.d.c

Reputation: 47988

Your for loop looks good, you probably want to use == instead of is to get it working. In Python the is operator compares two objects' identities.

I do seem to be able to compare lists, contrary to one of the comments:

>>> a = [u' ']
>>> a is [u' ']
False
>>> a == [u' ']
True

Upvotes: 2

Related Questions