I have a text file that looks like this:

tomato 7000
potato and pear 8000
prunes 892
tomato 8
carrot 600
prunes 3

To turn it into a dictionary that ignores the lines where there are more words (which is what I want, so potato and pear are ignored, which is fine), I wrote:

with open("C:\\path\\food.txt", encoding="utf-8") as f_skipped:
    result = {}
    for line in f_skipped:
        try:
            k, v = line.split()
        except ValueError:
            pass
        else:
            result[k] = v
        

But since there can't be duplicate keys, it takes the value that appears later, so tomato and prunes have values 8 and 3, respectively. Is there any way of taking only the first appearance and ignoring the later once?

I thought of keeping my code and just turning the text around (sounds a bit silly) or detecting whether there are duplicate words (the latter is a bit risky since there are lots of rows with many words that I simply wanna ignore anyway).

CodePudding user response：

Try this .get(key) method of the dictionary will return None if the key doesn't exit otherwise return the value for the key. so you can use it in if condition. I hope this is what you want by reading your question.

filename = "text.txt"
with open(filename, encoding="utf-8") as f_skipped:
    result = {}
    for line in f_skipped:
        try:
            k, v = line.split()
        except ValueError:
            pass
        else:
            if result.get(k) is None: 
                result[k] = v

    print(result)

Output

py code.py
{'tomato': '7000', 'prunes': '892', 'carrot': '600'}

CodePudding user response：

Try this:-

with open('food.txt') as food:
    D = {}
    for line in food:
        t = line.split()
        k = ' '.join(t[0:-1])
        if not k in D:
            D[k] = t[-1]
    print(D)