擅长:python、mysql、java
<p>使用列表字典(Python2.7解决方案)很简单:</p>
<pre><code>#!/usr/bin/env python
import fileinput
categories={}
for line in fileinput.input():
# Skip the first line in the file (assuming it is a header).
if fileinput.isfirstline():
continue
# Split the input line into two fields.
ha_master, cat_id = line.strip().split(',')
# If the given category id is NOT already in the dictionary
# add a new empty list
if not cat_id in categories:
categories[cat_id]=[]
# Append a new value to the category.
categories[cat_id].append(ha_master)
# Iterate over all category IDs and lists. Use ','.join() to
# to output a comma separate list from an Python list.
for k,v in categories.iteritems():
print '%s,%s' %(k,','.join(v))
</code></pre>