Victor Subervi wrote:
Hi;
This "pseudo-code" snippet was given to me by Dennis on this list (whose
last name escapes me):
def printTree(allTrees, level=0):
tree = []
for aTree in allTrees:
for name in sorted(aTree.keys()):
tree.append("%s%s" % ("\t" * level, name))
printTree(aTree[name], level + 1)
return tree
The code returns all the categories ("name") just fine. It doesn't, however,
increment level. I know from my tests that printTree is only called twice
(once for each store) and about half a dozen times recursively within one of
It increments just fine, but you don't use the values it then
generates. See below.
those stores. Why doesn't this increment? Full code follows.
TIA,
beno
#!/usr/bin/python
import sys,os
sys.path.append(os.getcwd())
import MySQLdb
from login import login
import re, string
def printTree(allTrees, level=0):
tree = []
for aTree in allTrees:
for name in sorted(aTree.keys()):
tree.append("%s%s" % ("\t" * level, name))
printTree(aTree[name], level + 1)
print '1'
return tree
You have to decide what printTree is intended to do. Is it printing
stuff (which the name implies), or is it building a result list (which
the return statement implies) ? From the rest of the code, I assume the
latter. So give it a different name, and fix the recursion.
When it recurses, it doesn't use the return value from the inner call.
Presumably you want to "extend" the list called "tree" each time you
recurse. At this point, you also have to decide what order the combined
list needs to be in, but maybe you've already done that.
def expand(fetched):
aDict = {}
for (name, ) in fetched:
aDict[name] = {}
return aDict
def getChildren(levelDict, store, level = 0):
user, passwd, db, host = login()
db = MySQLdb.connect(host, user, passwd, db)
cursor = db.cursor()
MAXLEVEL = 7
if level > MAXLEVEL:
return #possibly the data has a cycle/loop
for name, data in levelDict.iteritems():
sql = '''select * from categories%s as c
inner join categoriesRelationships%s as r
on c.ID = r.Child
inner join categories%s as p
on r.Parent = p.ID
where p.Category = "%s"''' % (store[0].upper() + store[1:],
store[0].upper() + store[1:], store[0].upper() + store[1:], name)
cursor.execute(sql)
levelDict[name] = expand(cursor.fetchall())
# recursive call to do next level
getChildren(levelDict[name], level + 1)
# no data return as we are mutating dictionaries in place
def catTree(allStores):
user, passwd, db, host = login()
db = MySQLdb.connect(host, user, passwd, db)
cursor = db.cursor()
finalTrees = []
returnFlag = ''
for store in allStores:
allTrees = []
sql = 'create table if not exists categories%s (ID int(3) unsigned
primary key auto_increment, Category varchar(40), Parent varchar(40));' %
(store[0].upper() + store[1:])
cursor.execute(sql)
sql = 'create table if not exists categoriesRelationships%s (ID integer
auto_increment primary key, Parent integer not null, foreign key (Parent)
references categories%s (ID), Child integer not null, foreign key (Child)
references categories%s (ID), check (Parent <> Child) );' %
(store[0].upper() + store[1:], store[0].upper() + store[1:],
store[0].upper() + store[1:])
cursor.execute(sql)
cursor.execute('select Category, Parent from categories%s;' %
(store[0].upper() + store[1:]))
data = cursor.fetchall()
cursor.execute('select Category from categories%s order by Parent, ID;'
% (store[0].upper() + store[1:]))
Categories = [itm[0] for itm in cursor] #untuple single column
if len(Categories) > 0:
cursor.execute('select Parent from categories%s order by Parent, ID;'
% (store[0].upper() + store[1:]))
Parents = [itm[0] for itm in cursor]
MAXLEVEL = 15
# get top level
cursor.execute('select category from categories%s order by Category;'
% (store[0].upper() + store[1:]))
theTree = expand(cursor.fetchall())
getChildren(theTree, store)
db.commit()
allTrees.append(theTree)
returnFlag = 'gotStuff'
else:
returnFlag = 'gotNoStuff'
finalTrees.append(printTree(allTrees))
Possibly you wanted extend() here, not append. As it stands now, you
get a list of lists.
if returnFlag == 'gotStuff':
return finalTrees
else:
return ''
Do you really mean to return a list if "gotStuff", and a string if not
? That puts a burden on your caller, and doesn't agree with the
docstring you didn't write.
Incidentally, good naming would help to make the code easier to debug.
This finalTrees and trees variables don't look to me like you intended
them to be trees at all, but lists of tab-indented data.
DaveA
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