How to replace the same lowercase and uppercase letters with a number in Python?

Question

1)How do I replace uppercase A and lowercase 'a' with number 1 ?

encrp_key = input('Enter the number 1' )               
msg = input('Enter some lowercase and some uppercase')              
    if encrp_key == 1:
        new_msg = msg.replace('a ','1').replace('e','2')\
                  .replace('i','3').replace('o','4').replace('u','5')

                ## if user types 'ABBSAS acbdcd '
                #   how do i replace 'A' and 'a' with 1 , E and e with 2 and                                                       
                #   I and i with 3   and so on.

http://stackoverflow.com/questions/3411771/multiple-character-replace-with-python — jkr, Jan 25 '17 at 14:46
`encrp_key` - what for? while *'A' and 'a' with 1 , E and e with 2 and # I and i with 3* — RomanPerekhrest, Jan 25 '17 at 14:46
if user enters 1 as encrp_key and msg input contains say ' I want to encrypt My MeSSages'. Then all uppercase and lower case A /a should be replaced with number 1. — rajiv sharma, Jan 25 '17 at 15:01
Something different: `''.join(map(str,('aeiou'.find(c.lower())+1 or c for c in msg)))` — Chris_Rands, Jan 25 '17 at 15:02

falsetru · Answer 1 · 2017-01-25T15:10:28.697

3

Using str.translate:

>>> tbl = {ord(c): str(i) for i, ch in enumerate('aeiou', 1)
                          for c in [ch, ch.upper()]}
>>> # OR   tbl = str.maketrans('aeiouAEIOU', '1234512345')
>>> tbl  # Make a mapping of old characters to new characters
{97: '1', 101: '2', 73: '3', 65: '1', 105: '3', 79: '4', 111: '4',
 117: '5', 85: '5', 69: '2'}
>>> 'Hello world'.translate(tbl)
'H2ll4 w4rld'

edited Jan 25 '17 at 15:10

answered Jan 25 '17 at 14:49

falsetru

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Can show me to do in a simple way without using for loop or dictionary . Just using replace() and if else? I am a beginner. – rajiv sharma Jan 25 '17 at 14:56
@rajivsharma Without using a loop or a dictionary, you're mostly relegated to what you've already done (i.e. using a lot of `str.replace` methods). Not too many of the answers here - while they're great and very Pythonic - are necessarily "beginner." – blacksite Jan 25 '17 at 15:04

Mohammad Yusuf · Answer 2 · 2017-01-25T18:12:48.353

1

Make a translation table with maketrans. Corresponding elements are mapped together.

from string import maketrans

tbl = maketrans('aAeEiIoOuU','1122334455')
print "aAeEiIoOuU".translate(tbl)

Output:

1122334455

Or you can do it like so:

from string import maketrans

tbl = maketrans('aeiou','12345')
print "aAeEiIoOuU".lower().translate(tbl)

Output:

1122334455

from string import maketrans

tbl = maketrans('aAeEiIoOuU','1122334455')

msg = input('Enter a sentence: ')
enc_key = int(input('Enter 1 for encryption, 0 for orignal text: '))

if enc_key == 1:
    print(msg.translate(tbl)) 
else:
    print(msg)

Output:

Enter a sentence: I want to encrypt My MeSSages
Enter 1 for encryption, 0 for orignal text: 1
3 w1nt t4 2ncrypt My M2SS1g2s

edited Jan 25 '17 at 18:12

answered Jan 25 '17 at 14:53

Mohammad Yusuf

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Can show me to do in a simple way without using for loop or dictionary . Just using replace() and if else? I am a beginner – rajiv sharma Jan 25 '17 at 14:56
@rajivsharma `string` module comes shipped with Python. Other than that it's all simple. – Mohammad Yusuf Jan 25 '17 at 15:00
My question is if user enters 1 as encrp_key and msg input contains say ' I want to encrypt My MeSSages'. Then all uppercase and lower case A /a should be replaced with number 1. – rajiv sharma Jan 25 '17 at 15:04
@rajivsharma What Python version are you using? Whats wrong with your current code? – Mohammad Yusuf Jan 25 '17 at 15:15
Python 3.6 is what I am using – rajiv sharma Jan 25 '17 at 17:09
@rajivsharma Check now. – Mohammad Yusuf Jan 25 '17 at 17:38

score 0 · Answer 3 · answered Jan 25 '17 at 15:04

0

Just another approach:

st = "abbrwerewrfUIONIYBEWw"
d = {v: str(i+1) for i, v in enumerate(list("aeiou"))}
for v in st:
    v = v.lower()
    if v in d:
        st  = st.replace(v, d[v])

answered Jan 25 '17 at 15:04

petruz

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How to replace the same lowercase and uppercase letters with a number in Python?

3 Answers3