if and else clauses

[shanazzle]

i have to do a project outlined at this link:
http://pages.cpsc.ucalgary.ca/~schoc...07_CPSC_217_A2

im currently doing part 2, involving searching for information from a cat data bank and having an output of the relevent sections. i've made 5 if statements where if the data from the search key if found in the data base, it will append into a second list and finally it will print the second list with all matching criteria. this code works well, but i need to have an else clause that will print " information not found" if there are no matches. my current code is:

[code removed at posters request]

but there are many errors, it prints the else clause, then the list of matches, then the else clause again. i dont know how to format this code to make it only print the else clause if data is not found. if i remove the else statement, the program works fine. What is wrong with my current code and what can i do to fix it?

[elcron]

An else statement is executed if the last if statement and all elif(else if in some languages) between fail. heres a commented example.

someCondition = input("> ")
 
# if a
if someCondition == 1:
    print 'if a'
 
# if b
if someCondition == 2:  # is checked whether or not 'if a' failed
    print 'if b'
elif someCondition == 3: # is checked only if 'if b' is checked and is false
    print 'elif b'
else:                             # code under this statement is only executed if 'if b' and the following elif statement are both false
    print 'else'
 

So this code should fix your if statements:

#
    if Key in cat[0].lower() and not cat_added: 
        Output_list.append(cat) 
        cat_added = 1
    elif Key in cat[1].lower() and not cat_added:
        Output_list.append(cat)
        cat_added = 1
    elif Key in cat[2].lower() and not cat_added:
        Output_list.append(cat)
        cat_added = 1
    elif Key in cat[3].lower() and not cat_added:
        Output_list.append(cat)
        cat_added = 1
    elif Key in cat[4].lower() and not cat_added:
        Output_list.append(cat)
        cat_added = 1    
        print Output_list
    else:
        print "There is no cat matching your description"
        break
 

Though it would be more readable as:

#...
success = False
for i in range(5):
     if Key in cat[i].lower() and not cat_added: 
          Output_list.append(cat) 
          cat_added = 1
if not success:
     print Output_list
else:
     print "There is no cat matching your description"
 

[bvdet]

Here's another way using a list comprehension:

Key = raw_input ("Enter Search Key:")
Output_list = [', '.join(item) for item in Cats if Key.lower() in [s.lower() for s in item]]
 
if Output_list:
    print '\n'.join(Output_list)
else:
    print 'No matching record found'

Example, enter 'LYNX':
>>> Carnivora, Felidae, Lynx, lynx, Lynx- Eurasian, 9 - 38 kg (20 - 83 lbs)
Carnivora, Felidae, Lynx, pardinus, Lynx- Iberian, 8.7 - 14.5 kg (19 - 32 lbs)
Carnivora, Felidae, Lynx, canadensis, Lynx - Canadian, 8 - 14 kg (18 - 30 lbs)
Carnivora, Felidae, Lynx, rufus, Bobcat, Red Lynx, 5.8 - 13.3 kg (13 - 30 lbs)

Example, enter 'RED LYNX':
>>> No matching record found