how to count articles in dictionary in python - python-2.7

Question

I am wanting to make a count of items in the dictionary. When a user enters a value to search, it finds the value's key, then returns the next key before it. i.e.({john:fred, fred: bill})
if the user enters john, it will return bill and vice versa.
My code is:
myDict = {}
with open("names.dat") as f:
for line in f:
for pair in line.strip ().split(', '):
i = 0
x = 0
(key, val) = pair.split (":")
myDict[key.strip(":")] = val
print "father: ", key , " son: ", val
def findFather (myDict, lookUp):
father = ""
for key, val in myDict.iteritems( ):
if val == lookUp:
key = key
father = key
return father
lookUp = raw_input ("Enter a son's name: ")
print findFather(myDict, lookUp)
the dictionary values are:
john:fred, fred:bill, sam:tony, jim:william, william:mark, krager:holdyn, danny:brett, danny:issak, danny:jack, blasen:zade, david:dieter, adam:seth, seth:enos

Answer 1

According to your comments, you're trying to find the grandfather of a person in a database mapping people to their fathers:
def read_db(fname):
with open(fname) as f:
return dict(pair.split(":")
for pair in line.strip().split(", ")
for line in f)
def grandfather(db, person):
return db.get(db.get(person)) # same as db[db[person]] except returns None when no match found instead of error
def main():
DB = read_db("names.dat")
print "\n".join("father: %s son: %s" % pair for pair in DB)
person = raw_input("Enter a son's name: ")
print grandfather(DB, person) # prints None if no father or no grandfather found
main()
As you can see, DB is the only needed variable in the entire program (person in main can also be inlined); in your question, your code contains a lot of noise that does absolutely nothing preventing you from understanding your code and making your question look very untidy. So try to clean everything up next time you ask a question on Stack Overflow. Also, check out the almighty PEP8!