Python将csv数据导出到文件中

Question

I have following code which works well but I am not able to trim and store a data in a datafile:

import nltk

tweets = [
    (['love', 'this', 'car']),
    (['this', 'view', 'amazing']),
    (['not', 'looking', 'forward', 'the', 'concert'])
    ]

def get_words_in_tweets(tweets):
    all_words = []
    for (words) in tweets:
      all_words.extend(words)
    return all_words

def get_word_features(wordlist):
    wordlist = nltk.FreqDist(wordlist)
    word_features = wordlist.keys()
    return word_features

output = open('wordFeatures.csv','w')

word_features = get_word_features(get_words_in_tweets(tweets))

print (word_features)
output.write(word_features)
#print (wordlist)
output.close()

What it does is, it checks if words a double or triple etc and only adds one word in the list. The output looks like this:

['this', 'amazing', 'car', 'concert', 'forward', 'looking', 'love', 'not', 'the', 'view']

Now as you can see I tried to save this data in a textfile but I get an

TypeError: expected a character buffer object

I want the data from the array in a textfile in the following format:

1:this
2:amazing
3:car 
4:concert
5:forward
...

so one row for every word with an increasing integer.

Has someone an idea how to save my data in this way?

Answer 1

The reason for the error is that output.write accepts a string, not a list . word_features is a list .

To write a list to a file, you will need to iterate over it:

for feature in word_features: 
    output.write("{0}\n".format(feature))

I don't understand the format you need because of the car and concert coming together on the same line. I am assuming that is a typo and you actually need them on separate lines. Then you can do this to obtain that output:

for nfeature in enumerate(word_features):
    output.write("{0}:{1}\n".format(nfeature[0] + 1, nfeature[1]))

Answer 2

You're trying to write a list object to a file, but it expects a string. You can use `enumerate here:

word_features = get_word_features(get_words_in_tweets(tweets))
with open('wordFeatures.csv', 'w') as output:
    for ind, item in enumerate(word_features, 1):
        output.write("{}:{}\n".format(ind, item))

or using csv module :

import csv
word_features = get_word_features(get_words_in_tweets(tweets))
with open('wordFeatures.csv', 'w') as output:
    writer = csv.writer(output, delimiter=':')
    writer.writerows(enumerate(word_features, 1))

Output:

1:this
2:amazing
3:car
4:concert
5:forward
6:looking
7:love
8:not
9:the
10:view

Answer 3

In Python, I save data into a csv file, but in a rather hack way:

First I save my data into a text file. In each row, I separate each "column element" with a comma.

Then, when I'm done with that row [currently just a line in a text file], I write in a new line and begin writing in the next line of data. Repeat as desired.

Then, when I'm all done, I re-name the text file into a csv file.

For you, adding in the increasing integer, you could make up an increment counter. If you were to do as I have, you could increment your counter, write the value into the text file, write in the comma, write in your data, and then write in a new line, then repeat. Just remember to re-name the file into a csv file when you're all done.

Like I said, a hack way of doing it but whichever. I'm open to hearing better methods.