6

我有一个名为“names.txt”的文件，其内容如下：

{"1":[1988, "Anil 4"], "2":[2000, "Chris 4"], "3":[1988, "Rahul 1"],
"4":[2001, "Kechit 3"], "5":[2000, "Phil 3"], "6":[2001, "Ravi 4"],
"7":[1988, "Ramu 3"], "8":[1988, "Raheem 5"], "9":[1988, "Kranti 2"],
"10":[2000, "Wayne 1"], "11":[2000, "Javier 2"], "12":[2000, "Juan 2"],
"13":[2001, "Gaston 2"], "14":[2001, "Diego 5"], "15":[2001, "Fernando 1"]}

问题陈述：文件“names.txt”包含一些学生记录，格式为 -

{"number": [year of birth, "name rank"]}

解析此文件并根据年份将它们隔离，然后根据排名对名称进行排序。先分拣，再分拣。输出应采用以下格式 -

{year : [Names of students in sorted order according to rank]}

所以预期的输出是 -

{1988:["Rahul 1","Kranti 2","Rama 3","Anil 4","Raheem 5"],
2000:["Wayne 1","Javier 2","Jaan 2","Phil 3","Chris 4"],
2001:["Fernando 1","Gaston 2","Kechit 3","Ravi 4","Diego 5"]}

首先如何将此文件内容存储在字典对象中？然后按年份分组然后按等级排序名称？如何在 Python 中实现这一点？

谢谢..

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2 回答 2

1

它非常简单:)

#!/usr/bin/python
# Program: Parsing, Aggregating & Sorting text file in Python
# Developed By: Pratik Patil
# Date: 22-08-2015

import pprint;

# Open file & store the contents in a dictionary object
file = open("names.txt","r");
file_contents=eval(file.readlines().pop(0));

# Extract all lists from file contents
file_contents_values=file_contents.values();

# Extract Unique Years & apply segregation
year=sorted(set(map(lambda x:x[0], file_contents_values)));
file_contents_values_grouped_by_year = [ [y[1] for y in file_contents_values if y[0]==x ] for x in year];

# Create Final Dictionary by combining respective keys & values
output=dict(zip(year, file_contents_values_grouped_by_year));

# Apply Sorting based on ranking
for NameRank in output.values():
    NameRank.sort(key=lambda x: int(x.split()[1]));

# Print Output by ascending order of keys
pprint.pprint(output);
于 2015-10-14T09:10:57.530 回答
-1

隔离可以通过collections.defaultdict一个简单的循环来完成。然后对学生列表进行另一个循环，以根据学生条目最后一部分的整数值对它们进行排序。如果我们将其转换为常规pprint()输出，则打印所需的输出：defaultdict

#!/usr/bin/env python
from __future__ import absolute_import, division, print_function
import json
from collections import defaultdict
from pprint import pprint


def main():
    with open('test.json') as student_file:
        id2student = json.load(student_file)
    # 
    # Segregate by year.
    # 
    year2students = defaultdict(list)
    for year, student_and_rank in id2student.itervalues():
        year2students[year].append(student_and_rank.encode('utf8'))
    # 
    # Sort by rank.
    # 
    for students in year2students.itervalues():
        students.sort(key=lambda s: int(s.rsplit(' ', 1)[-1]))

    pprint(dict(year2students))


if __name__ == '__main__':
    main()
于 2015-08-22T12:35:42.320 回答