CODEWITHSUNDEEP
pythonlistfor-loop
user1261774
user1261774

Reputation: 3695

replace if else with a for loop

I have a dynamic list of integers that often changes and I want to be able to find the next highest occurance in the list. This is the output of my list at the moment:

[u'4', u'32', u'72', u'100']

I have written a very long if else statement to confirm that my thinking/approach does work. I now want to be able to replace the if else statement with a for loop (i think a for loop should be best here), but I am having many problems in writing the for loop.

How do I replace the following if else statement with a for loop?

if unicode(new_val_xx) in resume_menu_list01:
    if unicode(int(new_val_xx)+1) in resume_menu_list01:
        next_page = int(new_val_xx)+1
    elif unicode(int(new_val_xx)+2) in resume_menu_list01:
        next_page = int(new_val_xx)+2
    elif unicode(int(new_val_xx)+3) in resume_menu_list01:
        next_page = int(new_val_xx)+3
    elif unicode(int(new_val_xx)+4) in resume_menu_list01:
        next_page = int(new_val_xx)+4
    elif unicode(int(new_val_xx)+5) in resume_menu_list01:
        next_page = int(new_val_xx)+5
    .....
    elif unicode(int(new_val_xx)+97) in resume_menu_list01:
        next_page = int(new_val_xx)+97
    elif unicode(int(new_val_xx)+98) in resume_menu_list01:
        next_page = int(new_val_xx)+98
    elif unicode(int(new_val_xx)+99) in resume_menu_list01:
        next_page = int(new_val_xx)+99

Also, what does the u before each value in my list represent (u'4')?

Thanks.

Upvotes: 0

Views: 211

Answers (2)

Burhan Khalid
Burhan Khalid

Reputation: 174728

There are three steps:

  1. Convert your unicode strings to integers.
  2. Find the maximum integer in your list.
  3. Add one to the maximum to get your next highest value.

Here are the three steps:

list_of_numbers = map(int, resume_menu_list01)
# if you are using Python3, list_of_numbers = list(map(int, resume_menu_list01))
maximum_number = max(list_of_numbers)
next_highest = maximum_number + 1

You can combine them all in one expression:

next_highest = max(map(int, resume_menu_list01))+1

next_highest = max(map(int, resume_menu_list01))+1 will return the max number plus one, which is not in the list. If I have the number 4 and I want to find the next highest number, which is 32, how would I write the for loop?

Do you just want to sort the list so you can step through it in acending order? If so, sorted_list = sorted(resume_menu_list01, key=int); but to find the higest value in the existing list, use max:

>>> i = [u'4', u'32', u'72', u'100']
>>> print(max(map(int, i)))
100

Now, if you want to know what is the next highest value from a known value:

known_value = u'4'
def get_highest(value, items):
   sorted_items = sorted(items, key=int)
   if sorted_items.index(value) == len(sorted_items) - 1:
      # The value is the highest item in the list
      # return the item
      return value
   else:
      return sorted_items[sorted_items.index(value)+1]

print(get_highest(known_value, [u'4', u'32', u'72', u'100']))

Upvotes: 1

CrazyGeek
CrazyGeek

Reputation: 3447

for new_val_xx in range(1,99):
     if unicode(new_val_xx) in resume_menu_list01:
         next_page = int(new_val_xx)+new_val_xx

This is what you want? otherwise @Burhan Khalid's answer is more optimized.

Upvotes: 0

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