Python function 用于判断字符串中的两个单词是否以相同的字母开头

Question

this is my first post here and I am a complete beginner(only been coding for a week or so) so please pardon me if Ive made some very dumb mistakes

Write a function takes a two-word string and returns True if both words begin with the same letter(capitalisation does not matter) and false otherwise

SOLUTION:

def prob2(b):
for p,q in b.split():
    if p[0] == q[0]:
        return(True)
    else:
        return(False).

If I try it with a string like 'hello world', I get the error message:

too many values to unpack, expected 2

But if I try it with a string like 'dc' i get the desired output, which makes it obvious that its splitting the string after each letter, not on the whitespace, which is weird, because i did not make any changes and by default it should be splitting on the whitespace.

Please tell me how I can fix this, thanks!

Answer 1

b.split() returns a list of space-separated words. Break this into component steps:

seq = b.split()
p, q = seq[0]
if p[0] == q[0]:
    return True
else:
   return False

This will work only when the first element of seq is some iterable of length 2. In short, a 2-letter string will work, comparing those two letters... d and c in your example.

Following the above break-down in your two-word case, we get the attempted assignment

p, q = "hello"

This tries to unpack 5 characters to two variables, causing your error.

Simply splitting a two-word string requires no loop, as others have shown:

p, q = b.split()

Or, safer yet, simply slice off the first two words:

p, q = seq[:2]
seq = seq[2:]     # remove the first two words from the `split` sequence

Also, note that your return can be much simpler: you already evaluated the Boolean result you want in the if expression.

p, q = seq[:2]
return p[0] == q[0]

Answer 2

it may have more items in the list, when you split the string by white space. you could print it out to see

def prob2(b):
    p,q = b.split()
    return p[0].lower() == q[0].lower()

Answer 3

for p,q in b.split() is not doing what you think.

Use p,q = b.split() instead.

Answer 4

When doing for p,q in b.split() this need that every element returned from the split() can be unpack in 2, this is the case of dc->d,c but each word of Hello Word canno't be unpacked in 2

Also you don't need to loop, as you need to look only at the first char, just do

def prob2(content):
    words = content.split()
    return len(words) == 2 and words[0].lower() == words[1].lower()