用mapreduce 处理气象数据集

cd /usr/hadoop
sodu mkdir qx
cd /usr/hadoop/qx

wget -D --accept-regex=REGEX -P data -r -c ftp://ftp.ncdc.noaa.gov/pub/data/noaa/2017/1*

cd /usr/hadoop/qx/data/ftp.ncdc.noaa.gov/pub/data/noaa/2017
sudo zcat 1*.gz >qxdata.txt
cd /usr/hadoop/qx

#！/usr/bin/env python
import sys
for i in sys.stdin:
     i = i.strip()
     d = i[15:23]
     t = i[87:92]

     print ‘%s\t%s‘ % (d,t) 

#!/usr/bin/env python
from operator import itemggetter
import sys

current_word = None
current_count = 0
word = None

for i in sys.stdin:
     i = i.strip()
     word,count = i.split(‘\t‘, 1)
     try:
          count = int(count)
     except ValueError:
          continue

     if current_word == word:
         if current_count > count:
              current_count = count
     else:
         if current_word:
             print ‘%s\t%s‘ % (current_word, current_count)
         current_count = count
         current_word = word

if current_word == word:
     print ‘%s\t%s‘ % (current_word, current_count)

chmod a+x /usr/hadoop/qx/mapper.py
chmod a+x /usr/hadoop/qx/reducer.py