topic Re: update cursor using a wildcard in Python Questions

update cursor using a wildcard

jameljoseph — Thu, 17 Mar 2016 19:32:44 GMT

hello,

I am using an update cursor in my python script to go through my table records and I want to assign the same value to all the universities that start with "University of".

Here is an example of what I want to do:

if row[0] == "Boston College":

[code here]

elif row[0] == "University of *":

[code here]

else:

I thought the * was the wildcard but all my records that have "University of" as the prefix in a record do not have any values in them, whereas Boston College does.

Re: update cursor using a wildcard

roemhildtg — Thu, 17 Mar 2016 19:41:47 GMT

The star operator only works for the UpdateCursor fields parameter. I think in this case you can use the `in` operator:

elif 'University of' in row[0]:

#do stuff

Re: update cursor using a wildcard

DanPatterson_Retired — Sat, 11 Dec 2021 15:43:50 GMT

there are a variety of ways, here is one

>>> a = "university of"
>>> b = "university of pythonia"
>>> 
>>> a in b
True
>>> "college" in b
False

Re: update cursor using a wildcard

DarrenWiens2 — Sat, 11 Dec 2021 15:43:53 GMT

For your purposes, 'in' should work, however it doesn't guarantee that the string starts with those characters. I'll just point out that there is 'startswith()' that tests string beginnings:

>>> a = "university of"  
... b = "university of pythonia"
... c = "pythonia university of"
... print b.startswith(a) # does b start with a?
... print c.startswith(a) # does c start with a?
... 
True
False

or, an alternative using slice notation:

>>> a = "university of"  
... b = "university of pythonia"
... c = "pythonia university of"
... print b[:len(a)] == a # do the first few items (letters) in b equal a?
... print c[:len(a)] == a # do the first few items (letters) in c equal a?
... 
True
False

Re: update cursor using a wildcard

DanPatterson_Retired — Thu, 17 Mar 2016 20:21:46 GMT

then you could have the best of both worlds

>>> a = "university of pythonia"

>>> "pythonia" in a.split(" ")

True

Re: update cursor using a wildcard

DarrenWiens2 — Sat, 11 Dec 2021 15:43:56 GMT

I'll play along. If you're determined to use split to test a string beginning...

>>> a = "university of" 
... b = "university of pythonia"
... c = "pythonia university of"
... print b.split(a)[0] == '' # if b is split by a, is the first item in the returned list blank?
... print c.split(a)[0] == '' # if c is split by a, is the first item in the returned list blank?
...
True
False

Re: update cursor using a wildcard

DanPatterson_Retired — Sat, 11 Dec 2021 15:43:58 GMT

I will work on some numpy examples then

Update

2D question demonstrated...extendable to N dimensions

>>> arr
array([['university'],
       ['of'],
       ['pythonia']], 
      dtype='|S10')
>>> np.any(np.where(arr=="pythonia",True,False))
True

Re: update cursor using a wildcard

BlakeTerhune — Sat, 11 Dec 2021 15:44:01 GMT

I second Darren Wiens in using startswith()

if row[0] == "Boston College":
    # [code here]
elif row[0].startswith("University of "):
    # [code here]
else:
    # [code here]

Just make sure the field you're doing this on has only strings (text). The code above will error if it hits a number or date value.

Re: update cursor using a wildcard

jameljoseph — Fri, 18 Mar 2016 00:04:18 GMT

thanks everyone. I tried everything on here and the first thing that worked was startswith() so thanks everyone it works perfectly now!