Uppercase every other word in a string using split/join-CodePudding

I have a string:

string = "Hello World"

That needs changing to:

"hello WORLD"

Using only split and join in Python.

Any help?

string = "Hello World" 

split_str = string.split()

Can't then work out how to get first word to lowercase second word to uppercase and join

CodePudding user response：

OP's objective cannot be achieved just with split() and join(). Neither of those functions can be used to convert to upper- or lower-case.

The cycle class from the itertools module is ideal for this:

from itertools import cycle

words = 'hello world'

CYCLE = cycle((str.lower, str.upper))

print(*(next(CYCLE)(word) for word in words.split()))

Output:

hello WORLD

CodePudding user response：

The code below works for any number of words:

string = "Hello World"
words   =  string.split() # works also for multiple spaces and tabs
result  =  ' '.join((w.upper() if i&1 else w.lower()) for i,w in enumerate(words))
print(result)
# "hello WORLD"

CodePudding user response：

for many words:

make a list of words using split

connect everything with " " using join

inside we run through the list using i up to the length of this list

if this is an odd number, then upper otherwise lower (because the list is numbered from 0, and we need every second one)

string = "Hello World! It is Sparta!"
split_str  = string.split()
print(" ".join(split_str[i].upper() if i&1 else split_str[i].lower() for i in range(len(split_str))))

# hello WORLD! it IS sparta!

for two words (easy solution):

string = "Hello World"
split_str  = string.split()
print(' '.join([split_str[0].lower(),split_str[1].upper()]))

# hello WORLD