Upper Case Letters

[sneekula]

I have a text I want to search for all it's upper case letters, then present these letters unique and sorted. I welcome any suggestions.

Here's an exampmle:

alphabet = "abcdefghijklmnopqrstuvwxyz"
text1 = "LQZYdMDHPEdWOAVUCBDdsfTEFgdfGIRKwerJMSONPX"
text2 = ""
upper_letters = []

#P
for letter in text1:
    # Check to see if the letter is already in upper_letters
    if upper_letters.count(letter) == 1: 
        continue
    # If letter is uppercase, add it to upper_letters
    if letter in alphabet.upper():
        upper_letters.append(letter)
# Put list in alphabetical order
upper_letters.sort()
# Put list into string with nothing between the letters
text2 = "".join(upper_letters)
# Print the original string and the resulting string.
print "This is the text1 string: '%s'" % (text1)
print "This string contains only the uppercase letters in text1: '%s'" % (text2)

This takes a string of random letters, puts each upper case in a list (unless it's already in there), sorts the list, puts it into a string, and then prints it out.

I hope that helped.

[vegaseat]

You can use Python's regular expression module re, very powerful for text processing, but there is a somewhat steep learning curve ahead!

# exploring Python's regular expression module re

import re

# find all upper case letters in a text:
text = "This text has Upper and Lower Case Letters"
all_uppers = re.findall("[A-Z]", text)

# make elements unique and sorted
all_uppers = sorted(list(set(all_uppers)))
print all_uppers  # ['C', 'L', 'T', 'U']

[jrcagle]

Or if regular expressions are too painful, some kind of compromise:

def count_caps(s):
    d = {}
    caps = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    for i in caps:
        d[i] = s.count(i)
    return d

def print_caps(s):
   d = count_caps(s)

   # not 'for i in d' becuase dictionaries don't have guaranteed order
   for i in "ABCDEFGHIJKLMNOPQRSTUVWXYZ":  
      if d[i]:
        print i + ":" + str(d[i]), 

print_caps("ASDHbajksfhHHLASD")
A:2 D:2 H:3 L:1 S:2

Jeff

[sneekula]

Thanks Jeff, that is even fancier than I needed. Will come in handy though!

The re module seems to be nice, really don't have much trouble seeing the syntax, but I have a little problem understanding the one liner about making a list unique and sort.

[Ene Uran]

My humble contribution using a list comprehension:

# create a unique sorted list of all upper case letters in text
text = "This text has Upper and Lower Case Letters"
unique_list = []
[unique_list.append(c) for c in text if c.isupper() and c not in unique_list]
print sorted(unique_list)   # ['C', 'L', 'T', 'U']

Here is the breakdown of vegaseat's one liner as I see it:

text = "This text has Upper and Lower Case Letters"

uppers_raw = re.findall("[A-Z]", text)  # ['T', 'U', 'L', 'C', 'L']
uppers_set = set(uppers_raw)            # set(['C', 'U', 'T', 'L'])
uppers_list = list(uppers_set)          # ['C', 'U', 'T', 'L']
uppers_sorted = sorted(uppers_list)     # ['C', 'L', 'T', 'U']

So set() removes duplicates?

[vegaseat]

So set() removes duplicates?

Yes, going fom a list to a set then back to a list removes duplicates from the list, but it will change the order of the elements. So, only use this little trick when order does not matter.

[sneekula]

Looks like this code comes in handy too:

[I]# make elements in the list all_uppers unique and sorted[/I]
all_uppers = sorted(list(set(all_uppers)))

Thanks to all who helped!

[twekberg]

That's a lot of work. If I set the following:

a = 'ABCDEFGHIJKLMNOPQRSTUVWXYX'
b= 'A Rat In The House Might Eat The Ice Cream'

Then the following returns the result the original poster wanted:

>>> set(sorted([ch for ch in b if ch in a]))
set()