思路整理
1.打开文件，处理其中的每一行
2.将每个词添加到字典中更新其计数
3.显示输出，在此例中按频率高低进行排列
使用的python函数
Dict.items()：所有键值对的元组列表
str.strip():用于移除字符串头尾指定的字符（默认为空格）
list.append(obj)：用于在列表末尾添加新的对象
str.split():通过指定分隔符对字符串进行切片
函数定义
addWord:将每个单词添加到字典中
processLine：要处理行，还要完成剔除不同的字符，分割出单词等工作
prettyPrint:格式化的显示，将针对每种情况，将显示功能分离出来
main：使用主函数为主程序
addWord
def addWord(word,wordCountDict):
'''Update the word frequency:word is the key,frequency is the value.'''
if word in wordCountDict:
wordCountDict[word] += 1
else:
wordCountDict[word] = 1
processLine
import sting
def processLine(line,wcDict):
'''Process the line to get lowercase words to add to the dictionary.'''
line = line.strip()
wordList = line.split()
for word in wordList:
#ignore the '--' that is in file
if word != '--':
word = word.lower()
word = word.strip()
#get commas,periods and punctuation out as well
word = word.strip(string.punctuation)
addWord(word,wcDict)
prettyPrint
def prettyPrint(wcDict):
'''Print nicely from highest to lowest frequency.'''
#create a list of tuple,(value,key)
#valKeyList = [(val,key) for key,val in d.itemw()]
valKeyList = []
for key,val in wcDict.items():
valKeyList.append((val,key))
#sort method sorts on list's first element,here the frequency.
#Reverse to get biggest first
valKeyList.sort(reverse=True)
print '%-10s%10s' %('Word','Count')
print '_'*21
for val,key in valKeyList:
print '%-12s %3d' %(key,val)
main
def main():
wcDict = {}
fobj = open('gettysbury.txt','r')
for line in fobj:
processLine(line,wcDict)
print 'Length of the dictionary:',len(wcDict)
prettyPrint(wcDict)
最终代码如下：
# __author__ == 'xjiao'
# -*- coding:utf-8 -*-
import string
def addWord(word,wordCountDict):
'''Update the word frequency:word is the key,frequency is the value.'''
if word in wordCountDict:
wordCountDict[word] += 1 #如果单词在wordCountDict词典已存在，数量加1
else:
wordCountDict[word] = 1 #如果不存在，插入一条记录
def processLine(line,wcDict):
'''Process the line to get lowercase words to add to the dictionary.'''
line = line.strip() #去掉每行的空白
wordList = line.split() #去掉空白字符，分割字符
for word in wordList:
#ignore the '--' that is in file
if word != '--':
word = word.lower()
word = word.strip()
#get commas,periods and punctuation out as well
word = word.strip(string.punctuation)
addWord(word,wcDict)
def prettyPrint(wcDict):
'''Print nicely from highest to lowest frequency.'''
#create a list of tuple,(value,key)
#valKeyList = [(val,key) for key,val in d.itemw()]
valKeyList = []
for key,val in wcDict.items():
valKeyList.append((val,key))
#sort method sorts on list's first element,here the frequency.
#Reverse to get biggest first
valKeyList.sort(reverse=True)
print '%-10s%10s' %('Word','Count')
print '_'*21
for val,key in valKeyList:
print '%-12s %3d' %(key,val)
def main():
wcDict = {}
fobj = open('gettysburg.txt','r')
for line in fobj:
processLine(line,wcDict)
print 'Length of the dictionary:',len(wcDict)
prettyPrint(wcDict)
if __name__ == "__main__":
main()
输出结果如下：
D:\python\python.exe E:/python_project/gettysburg.py
Length of the dictionary: 136
Word Count
_____________________
the 15
that 11
we 10
to 9
here 9
of 6
and 6
a 6
nation 5
it 5
have 5
in 4
for 4
dedicated 4
who 3
us 3
this 3
they 3
so 3
shall 3
people 3
is 3
great 3
dead 3
cannot 3
are 3
which 2
what 2
war 2
these 2
rather 2
our 2
or 2
not 2
new 2
men 2
long 2
living 2
gave 2
from 2
field 2
far 2
devotion 2
dedicate 2
conceived 2
can 2
but 2
be 2
years 1
world 1
work 1
will 1
whether 1
vain 1
upon 1
unfinished 1
thus 1
those 1
their 1
testing 1
task 1
take 1
struggled 1
should 1
seven 1
sense 1
score 1
say 1
resting-place 1
resolve 1
remember 1
remaining 1
proposition 1
proper 1
power 1
portion 1
perish 1
on 1
now 1
note 1
nor 1
nobly 1
never 1
might 1
met 1
measure 1
lives 1
live 1
little 1
liberty 1
last 1
larger 1
increased 1
honored 1
highly 1
hallow 1
ground 1
government 1
full 1
freedom 1
four 1
fought 1
forth 1
forget 1
fitting 1
final 1
fathers 1
equal 1
engaged 1
endure 1
earth 1
do 1
died 1
did 1
detract 1
created 1
continent 1
consecrated 1
consecrate 1
come 1
civil 1
cause 1
by 1
brought 1
brave 1
birth 1
before 1
battle 1
as 1
any 1
altogether 1
all 1
ago 1
advanced 1
add 1
above 1
Process finished with exit code 0
