Looping String difficulty python 3

You should test if m is a space first; otherwise if the space occurs when i is even then i would not be reset:

string = 'Weird string case'
result = ''
i=0
for m in string:
    if(m==' '):
       result = result + m
       i=0
    elif(i%2==0):
       result = result+m.upper()
       i+=1
    else:
       result = result + m.lower()
       i+=1
    print(result)

This seems to have fixed it.

string = 'Weird string case'
result = ''
i=0
for m in string:
    if(i%2==0):
       result = result+m.upper()
       i+=1
    elif(m==' '):
       result = result + m
       i=1
    else:
       result = result + m.lower()
       i+=1
    print(result)

I was not explicitly asked for, but we could tokenize the string first. This makes it case the individual words:

import re
string = 'Weird string case'
result = ''
for word in re.split("\\s+", string):
    for index, char in enumerate(word, 1):
        result = result+char.lower() if index%2==0 else result + char.upper()
    result += " "
print(result)

A regular string.split(" ") works as well. I've just used regex for demonstration purpose.

little swaps can solve the problem:

string = 'Weird string case'
result = ''
i=0
for m in string:
    if(i%2!=0):
       result = result+m.lower()
       i+=1
    elif(m==' '):
       result = result + m
       i=0
    else:
       result = result + m.upper()
       i+=1
    print(result)

Or have a two-liner, (could be one very long tho), a list comprehension and a map and two joins:

s=''.join([i.lower() if idx%2 else i.upper() for idx,i in enumerate(string)]).split()
print(' '.join(map(lambda x: x.swapcase() if x[0].islower() else x,s)))

If we enumerate string we can trim down our if, elif, else statement to just an if, else that would be not i % 2 for our upper.() and else for lower. We can append them to a list and then use ''.join(res) to print the final product. Also map is an option and list comprehension

map

s = 'Weird string case'
res = list(map(lambda x: x.upper() if not s.index(x) % 2 else x.lower(), s))
print(''.join(res))

list comprehension

res = [v.upper() if not i % 2 else v.lower() for i, v in enumerate(s)]
print(''.join(res))

Full loop:

res = []

for i, v in enumerate(s):
    if not i % 2:
        res.append(v.upper())
    else:
        res.append(v.lower())

print(''.join(res))

WeIrD StRiNg cAsE

I would use another list

    string = 'Weird string case'
    words = string.split(" ") #This creates a list of substrings from your original string
    result = ''
    for word in words:
        for m in string:
            if(i%2==0):
               result = result+m.upper()
               i+=1
            elif(m==' '):
               result = result + m
               i=0
            else:
               result = result + m.lower()
               i+=1
           `enter code here` print(result)