Write a function in Python:
Given a list of words, indicate whetehr the list constitutes a "Word Ladder." A Word Ladder is a series of words where each succesding word changes by only one letter. You may assume that all words will be of the same length, but you may not assume the length of the list.
To determine whether a list of words constitutes a "Word Ladder" in Python, you can write a function that checks if each pair of consecutive words in the list differ by only one letter. Here's an example implementation of such a function:
```python
def is_word_ladder(words):
# Iterate through the list of words
for i in range(len(words) - 1):
word1 = words[i]
word2 = words[i + 1]
# Check if the current pair of words differ by only one letter
differences = sum(c1 != c2 for c1, c2 in zip(word1, word2))
# If there is more than one difference, return False
if differences != 1:
return False
# If all pairs of words differ by only one letter, return True
return True
```
In this function, we use a loop to iterate through the list of words. For each pair of consecutive words, we compare each corresponding pair of letters using `zip()`. The `sum()` function is then used to count the number of differences between the words.
If the number of differences is not equal to 1, we return `False`, indicating that the list does not constitute a Word Ladder. If all pairs of words pass the check, we return `True`, indicating that the list does constitute a Word Ladder.
You can call this function with a list of words as an argument to check whether it is a Word Ladder. For example:
```python
words = ["lead", "load", "goad", "gold", "cold"]
print(is_word_ladder(words)) # Output: True
words = ["lead", "load", "goad", "gold", "sold"]
print(is_word_ladder(words)) # Output: False
```
The first example returns True because each pair of consecutive words in the list differs by only one letter. The second example returns False because the pair "gold" and "sold" differs by more than one letter.