需要帮助遍历字典-Python

Question

I'm a beginner in Python. I have a simple dictionary called G8_Leaders.txt - as follows: {Cameron:UK, Merkel:Germany, Obama:USA, Putin:Russia} and I'm trying to iterate through the pairs - display the contents in a column, using a basic "for" loop like so:

f0 = "G8_Leaders.txt"
f1 = open(f0)
    for i in f1:
        print(i, end=" ")
    else:
        print("Finished with Document: ", f0)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'd like the results in a column, such as:

Merkel Germany

Cameron UK

Obama USA

and so on...However, the results are only printed in one line, as they are displayed in the text file.

What is the proper way to do this?

Answer 1

First, you have to fix the representation of your dictionary in your file to be as:

d = {'Cameron':'UK', 'Merkel':'Germany', 'Obama':'USA', 'Putin':'Russia'} It can be done programmatically by invoking str() on each key and value of d . Assuming that that is fixed, one solution would be:

# Create a file for test bench: 
d = {'Cameron':'UK', 'Merkel':'Germany', 'Obama':'USA', 'Putin':'Russia'}
with open("G8_Leaders.txt", "w") as f:
    f.write(str(d) +'\n')

#Read and print from the file:
with open("G8_Leaders.txt", "r") as f:
    data = f.readlines()
for line in data:
    d = eval(line)
    for y, z in d.items():
        print(y, z)

Output:

Cameron UK
Merkel Germany
Putin Russia
Obama USA

Answer 2

Ok, a couple things are going on here. f1 is a file object, which is not what you are expecting. If you want to access it as a string, you would do

`f1_string = f1.read()`

Which reads the file into the variable f1_string as a string. You could do:

for line in f1.readlines():
    # operate on one line at a time in this block

if you would prefer to read a line at a time, which will work in your case if each element is on its own line in the text file. Since we don't know what exactly what your text file looks like, it's hard to give more specific help. The json module people are referring to can be found here , but I'm not entirely sure that's what you want.

Answer 3

Assuming that your text file is just as you've described it, then try the following:

    with open(f0, 'r') as f:
        for line in f:
            items = line.split(',')
            for item in items:
                leader = item.split(':')[0].replace('{','')
                country = item.split(':')[1].replace('}','')
                print(leader,country)

This should work regardless of whether or not your data has line breaks in it.

Answer 4

Try this to iterate through a dictionary:

leaders = {'Cameron':'UK', 'Merkel':'Germany', 'Obama':'USA', 'Putin':'Russia'}
for leader in leaders:    
    print(leader, leaders[leader])

Answer 5

import json
print("\n".join(x+"  "+ y for x,y in json.load(open("fname.txt" ,"rb")).iteritems()))

just load it as json(at least I think its not entirely clear if you have properly formatted json in your text file ) ... (warning though dictionaries are unordered so if you need a certain order you will have to provide more clarification)