RichieJu

2012年3月6日星期二

enumerate用法

enumerate(sequence[, start=0]) )返回一个枚举对象，sequence必须是一个序列、迭代器或者具有具有迭代功能的对象。enumerate()是适用于获得索引集：(0, seq[0]), (1, seq[1]), (2, seq[2]), ....
>>> i = 0
>>> seq = ['one', 'two', 'three']
>>> for element in seq:
... seq[i] = '%d: %s' % (i, seq[i])
... i += 1
...
>>> seq
['0: one', '1: two', '2: three']
>>> seq = ['one', 'two', 'three']
>>> for i, element in enumerate(seq):
... seq[i] = '%d: %s' % (i, seq[i])
...
>>> seq
['0: one', '1: two', '2: three']
>>> def _treatment(pos, element):
... return '%d: %s' %(pos, element)
...
>>> seq = ['one', 'two', 'three']
>>> [_treatment(i, e1) for i, e1 in enumerate(seq)]
['0: one', '1: two', '2: three']

转自：http://greybeard.iteye.com/blog/1295827

2012年2月24日星期五

python+pyqt4脚本转exe程序
转换工具：Py2exe
运行平台：Windows

下面按步骤说明将一个Python脚本转换成exe程序的过程。
1. 安装Py2exe
2. 进入hello.py的目录，编写安装脚本setup.py。其内容如下：

1. 精简版+图标 pyqt4打包
#setup_pyqt.py
#with logo.ico and all the files bundled in one exe

name1=raw_input("Enter the name of py file: ")
from distutils.core import setup
import py2exe

setup(zipfile=None,
windows=[{"script" : name1, 'icon_resources':[(1, 'logo.ico')]}],
options={"py2exe" : {"includes" : ["sip"]},"py2exe": { "bundle_files": 1,"includes" : ["sip"] }})

2. 精简版：打包 python 脚本成带图标的exe 程序，无小文件生成

#setup_python.py
#with logo.ico and all the files bundled in one exe

name1=raw_input("Name of py file: ")
from distutils.core import setup
import py2exe
import sys
includes = ["encodings", "encodings.*"]
sys.argv.append("py2exe")
options = {"py2exe": { "bundle_files": 1,"includes" : ["sip"] } }
setup(options = options,
zipfile=None,
console = [{"script":name1, 'icon_resources':[(1, 'logo.ico')]}])

3. 打开DOS并切换其工作目录为当前目录，按如下方式在DOS中运行setup_pyqt.py, setup_python.py：

python setup_pyqt.py py2exe
python setup_python.py py2exe

2011年12月30日星期五

ID To Namelist

ID To Namelist

import os
import time, sys
from Bio import SeqIO

filename=raw_input("Pls enter the name of the output txt file of Blastall.exe: ")
Approach=raw_input("Pls enter the the approach of your Datebase: ")

# Timing start
start=time.time()
wrerr = sys.stderr.write

# Create a file named 'Results' in current dir
if os.path.exists('Results'):
for root, dirs, files in os.walk('Results'):
for name in files:
os.remove(os.path.join(root,name))
else:
os.mkdir('Results')

f=open(filename,'r')
f1=open('Results//ID_datebase.txt','w')

a={}
b=[]

# Search every dirs and files at F:\python missions\YY\Datebase
for root,dirs,files in os.walk(Approach):
for file in files:
for record in SeqIO.parse(os.path.join(root, file), 'fasta'):
b.append(record.id)
a[os.path.join(root, file).split('\\')[-2]+'-'+os.path.join(root, file).split('\\')[-1]]=b
b=[]

# Output ID_datebase
f1.write('Namelist'+'\t'+'Corresponding ID'+'\n')
for key in sorted(a.keys()):
f1.write(str(key)+'\t'+str(a[key])+'\n')

# Name the IDs
num=0

for line in f:
num+=1
for key in a.keys():
if line.split('\t')[1].strip() in str(a[key]):
f2=open('Results\\'+key+'.txt','a')
f2.write(str(line).strip()+'\t'+key+'\t'+'\n')
if num%100000==0:
print str(num)+" sequences have been processed!"

end=time.time()
wrerr("OK, All Work Finished in %3.2f secs\n" % (end-start))
raw_input("Press <Enter> to close this window: ")

2011年11月10日星期四

用Python的split输出excel文件

Here’s an example of some data where the dates not formatted well for easy import into Excel:

20 Sep, 263, 1148, 0, 1, 0, 0, 1, 12.1, 13.9, 1+1, 19.9

20 Sep, 263, 1118, 0, 1, 0, 360, 0, 14.1, 15.3, 1+1, 19.9

20 Sep, 263, 1048, 0, 1, 0, 0, 0, 14.2, 15.1, 1+1, 19.9

20 Sep, 263, 1018, 0, 1, 0, 360, 0, 14.2, 15.9, 1+1, 19.9

20 Sep, 263, 0948, 0, 1, 0, 0, 0, 14.4, 15.3, 1+1, 19.9

The first column has the day and month separated by a space. The second column is year-day, which we’ll ignore. The third column has the time. The data we’re interested in is in the 9th column (temperature). The goal is to have a simple Excel file where the first column is date, and the second column is temperature.

以上从某博客上见到的采用xlrd模块来写excel，感觉很复杂。自己也编写了一个python脚本来完成相同任务，如下所示：

f = open('weather.data.example.txt','r')

f1= open('result.xls','w')

for line in f:

L = line.strip().split(',')

if len(L) < 12:

continue

date = L[0].strip()

time = L[2].strip()

temperature = str(L[8])

f1.write(date+'-'+time+'-'+'\t'+temperature+'\n')

print 'OK, finished'

利用list(set())和sorted处理列表或字典

1.利用list(set(a))来删除列表a或者字典中重复的元素。

>>> a=['2','2','4','3','4','0','1','1']

>>> list(set(a))

['1', '0', '3', '2', '4']

2.利用sorted 来排序字典a。排序原则：将列表b中元素按照其在字典a中对应值的大小来排序。Reference: http://wiki.python.org/moin/HowTo/Sorting/

>>> a={'a': '3', 'c': '2', 'e': '1', 'd': '0'}
>>> b=['a','e']
>>> sorted(b,key=a.__getitem__)
['e', 'a']

特殊地：
对字典a的健值列表(a.keys()) 按其对应值的大小进行排序，结果输出到列表中

>>> a={'a':'3','c':'2','d':'0','e':'1'}
>>> sorted(a.keys(),key=a.__getitem__)
['d', 'e', 'c', 'a']