在 Python 中遍历字典

Question

I have a function that accepts a string parameter that represents a Spanish-language sentence and returns a new string that is, respectively, a translation of the English-language sentence.

According to the exercise I have, I have to translate every word in a sentence using the dictionary words that appear in the translate function.

def translate(sentence):  #  the function start here
words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 'el': 'the'}

This is the way to call a function, calling a function has the value of the sentence to be translated :

print(translate("el gato esta en la casa"))

Your ideas on how I approach the problem I tried alone without success

Answer 1

You are supposed to iterate over the sentence, not the dictionary. In most cases, if you need to iterate a dictionary you are probably doing something wrong.

def translate(sentence):  #  the function start here
    words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 
             'el': 'the'}
    return ' '.join(words[english_word] for english_word in sentence.split())

This will take in passed in Spanish sentence, split it to a list of words (splitting on whitespace), look up each word in the dict then put back everything together into a string using whitespace as a delimiter.

Of course this is a naive solution that will not care about correct grammar. or about missing words (hint: use try-except or dict.get to handle the latter).

print(translate("el gato esta en la casa"))
# the cat is in the house

Answer 2

How about something like this?

words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 'el': 'the'}


def translate(sentence):
    splitted_sentence = sentence.split()
    return ' '.join([words[word] for word in splitted_sentence])

print(translate("el gato esta en la casa"))

>> the cat is in the house

Answer 3

You can use a simple dictionary lookup using get so, you can handle KeyError :

def translate(sentence):  #  the function start here
    words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 'el': 'the'}
    return ' '.join(words.get(x, '') for x in sentence.split())

Answer 4

Python dictionary works this way : dictionary["key"] = value .

for your code I would suggest using the words in your sentence as keys. you will then get the values.

for example : words["el"] = "the"

def translate(sentence):  #  the function start here
    ret = ''
    words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 'el' : 'the'}
    for w in words:
        ret += words[w]+" "
    return ret
translate("el gato esta en la casa")

Answer 5

def translate(sentence):  #  the function start here
    words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 'el': 'the'}

    english_words = sentence.split()
    for word in english_words:
        yield words[word]

result = translate("el gato esta en la casa")
for res in result:
    print (res,end= " ")

I don't get why do you need a generator for this but whatever

this prints: the cat is in the house

just a small note since I see you asked some people if a generator needs the 'yield' part, the answer is no.

def translate(sentence):  #  the function start here
    words = {'esta': 'is', 'la': 'the', 'en': 'in', 'gato': 'cat', 'casa': 'house', 'el': 'the'}

    english_sentence = (words[word] for word in sentence.split())
    return type(english_sentence)

print(translate("el gato esta en la casa"))

this prints out: <class 'generator'>

basically if you " ".join(english_words) you will get the sentence you want