Re: Help counting the total number of dictionaries inside a list thatcontain a specified key value

[Jon Bowlas]

Hrmm, any ideas why I'd be getting 'SyntaxError: invalid syntax' for
both of these?

sum(u'Level 2 Courses' in dct for dct in yourlist)
q = set(['1']); print q, sum(d.get('leve l') in q for d in thelist)

The error occurs at the 'for'

I'm afraid I can't use Peters suggestion as I'm using python 2.3 and
it doesn't have the collection module. Thanks anyway.

Cheers

Jon

2008/8/12 Jon Bowlas <me@jonbowlas.c om>:

Many thanks for all your reponses, much appreciated.

I'll get back to you on which is the best for me.

BTW - yes John thats exactly what I wanted.

Cheers

Jon

Jon Bowlas wrote:

>For example I'd like to kow how many dictionaries there are with a
level 1, 2 , 23 & 3 etc. How would one go about achieveing this?

Hope someone can help.

sum(u'Level 2 Courses' in dct for dct in yourlist)

Christian

2008/8/12 Jon Bowlas <me@jonbowlas.c om>:

>Hi All,

I have the following list containing dictionaries and I would like to
be able to count the total number of dictionaries I have that contain
a certain value set for the 'level' key:

[{'mod_title': u'Introduction to Human Anatomy', 'level': u'1',
'modcode': u'ANAT1003', 'deptleveltext' : u'', 'deptlevelheade r':
u'Level 1 Courses', 'subj_code': u'AE'}, {'mod_title': u'Developmental
Neurobiology ', 'level': u'2', 'modcode': u'ANAT2008', 'deptleveltext' :
u'', 'deptlevelheade r': u'Level 2 Courses', 'subj_code': u'AE'},
{'mod_title' : u'Human Neuroanatomy', 'level': u'2', 'modcode':
u'ANAT2010', 'deptleveltext' : u'', 'deptlevelheade r': u'Level 2
Courses', 'subj_code': u'AE'}, {'mod_title': u'Human Anatomy and
Embryology', 'level': u'2', 'modcode': u'ANAT2050', 'deptleveltext' :
u'', 'deptlevelheade r': u'Level 2 Courses', 'subj_code': u'AE'},
{'mod_title' : u'Ethics of Fertility and Embryo Research', 'level':
u'2', 'modcode': u'ANAT2099', 'deptleveltext' : u'', 'deptlevelheade r':
u'Level 2 Courses', 'subj_code': u'AE'}, {'mod_title': u"Man's Place
in Nature 1750-1900", 'level': u'23', 'modcode': u'HMED3001',
'deptleveltext ': u'', 'deptlevelheade r': u'Level 2/3 Courses',
'subj_code': u'AE'}, {'mod_title': u'Medicine, Disease and Society,
Antiquity to Renaissance ', 'level': u'23', 'modcode': u'HMED3003',
'deptleveltext ': u'', 'deptlevelheade r': u'Level 2/3 Courses',
'subj_code': u'AE'}, {'mod_title': u'Madness and Society', 'level':
u'23', 'modcode': u'HMED3004', 'deptleveltext' : u'',
'deptlevelhead er': u'Level 2/3 Courses', 'subj_code': u'AE'}]

For example I'd like to kow how many dictionaries there are with a
level 1, 2 , 23 & 3 etc. How would one go about achieveing this?

Hope someone can help.

Cheers

Jon

[Peter Otten]

Jon Bowlas wrote:

Hrmm, any ideas why I'd be getting 'SyntaxError: invalid syntax' for
both of these?

>sum(u'Level 2 Courses' in dct for dct in yourlist)
q = set(['1']); print q, sum(d.get('leve l') in q for d in thelist)

The error occurs at the 'for'

I'm afraid I can't use Peters suggestion as I'm using python 2.3 and
it doesn't have the collection module. Thanks anyway.

John's suggestion uses a generator expression (new in 2.4). Try a list
comprehension instead:

q = set(['1']); print q, sum([d.get('level') in q for d in thelist])

You can modify my code to use normal dictionaries:

freq = {}
for course in courses:
level = course[u"level"]
freq[level] = freq.get(level, 0) + 1
print freq

Peter