python使用正则搜索字符串或文件中的浮点数代码实例

# -*- coding: utf-8 -*-
#----------------------------------------------------------------------
# FileName:gettxtdata.py
#功能:读取字符串和文件中的数值数据(浮点数)
#主要提供类似matlab中的dlmread和dlmwrite函数
#同时提供loadtxtdata和savetxtdata函数
#Data: 2013-1-10
#Author:吴徐平
#----------------------------------------------------------------------
import numpy
#----------------------------------------------------------------------
def StringToDoubleArray(String):
 """
 #将字符串中的所有非Double类型的字符全部替换成空格
 #以'#'开头注释直至行尾,都被清空
 #返回一维numpy.array数组

 """ 
 from StringIO import StringIO
 import re
 
 DataArray=numpy.empty([0],numpy.float64)

 if len(String.strip())>0:
 #清空注释行,都是以'#'开头子字符
 doublestring=re.sub('#.*$', " ", String, count=0, flags=re.IGNORECASE)
 #删除非数字字符 
 doublestring=re.sub('[^0-9.e+-]', " ", doublestring, count=0, flags=re.IGNORECASE)
 #去掉不正确的数字格式(代码重复是有必要的)
 doublestring=re.sub('[.e+-](?=s)', " ", doublestring, count=0, flags=re.IGNORECASE)
 doublestring=re.sub('[.e+-](?=s)', " ", doublestring, count=0, flags=re.IGNORECASE)
 doublestring=re.sub('[e+-]$', " ", doublestring, count=0, flags=re.IGNORECASE)
 doublestring=re.sub('[e+-]$', " ", doublestring, count=0, flags=re.IGNORECASE)
 #去掉首尾空格
 doublestring=doublestring.strip()
 if len(doublestring)>0:
 StrIOds=StringIO(doublestring)
 DataArray= numpy.genfromtxt(StrIOds)
 
 return DataArray

#----------------------------------------------------------------------
def GetDoubleListFromString(String):
 """
 #使用换行符分割字符串
 #将字符串中的所有非Double类型的字符全部替换成空格
 #以'#'开头注释直至行尾,都被清空
 #将每一行转换成numpy.array数组
 #返回numpy.array数组的列表

 """ 
 from StringIO import StringIO
 import re
 
 DoubleList=[]
 StringList=String.split('
')#使用换行符分割字符串
 for Line in StringList:
 if len(Line.strip())>0:
 #清空注释行,都是以'#'开头子字符
 doublestring=re.sub('#.*$', " ", Line, count=0, flags=re.IGNORECASE)
 #删除非数字字符 
 doublestring=re.sub('[^0-9.e+-]', " ", doublestring, count=0, flags=re.IGNORECASE)
 #去掉不正确的数字格式(代码重复是有必要的)
 doublestring=re.sub('[.e+-](?=s)', " ", doublestring, count=0, flags=re.IGNORECASE)
 doublestring=re.sub('[.e+-](?=s)', " ", doublestring, count=0, flags=re.IGNORECASE)
 doublestring=re.sub('[e+-]$', " ", doublestring, count=0, flags=re.IGNORECASE)
 doublestring=re.sub('[e+-]$', " ", doublestring, count=0, flags=re.IGNORECASE)
 #去掉首尾空格
 doublestring=doublestring.strip()
 if len(doublestring)>0:
 StrIOds=StringIO(doublestring)
 DoubleList.append(numpy.genfromtxt(StrIOds)) 
 return DoubleList
 
#----------------------------------------------------------------------
def GetDoubleListFromFile(FileName):
 """
 #将文本文件中的所有Double类型的字符全部替换成numpy.array数组
 #每一行都是numpy.array数组
 ##返回numpy.array数组的列表
 #注意:返回列表的每个元素又都是一个numpy.array数组
 #注意:返回列表的每个元素(或文件每行)可以包含不同多个数的数字

 """ 
 file=open(FileName, 'r')
 read_file = file.read()
 file.close() 
 DoubleList=GetDoubleListFromString(read_file)
 return DoubleList

def dlmread(FileName,dtype=numpy.float64):
 """
 #Load Data From Txt-File.
 #分隔符默认是:";",",",空格类 (包括	)等等
 #以#开头的被认为是注释,不会被读取
 #Return Value:二维数值数组(numpy.ndarray)
 #对文本中数据的排列格式要求最低,且容许出现注释字符,智能化程度最高,但速度较慢
 """
 DoubleList=GetDoubleListFromFile(FileName)
 dlsize=[]#每一行数组的大小
 for dL in DoubleList:
 dlsize.append(dL.size)
 
 MinColumnSize=min(dlsize)#数组的最大列数
 MaxColumnSize=max(dlsize)#数组的最小列数
 #数组创建和赋值
 DoubleArray=numpy.empty([len(DoubleList),MinColumnSize],dtype=dtype)
 
 row=range(0,len(DoubleList))
 colum=range(0,MinColumnSize)
 
 for i in row:
 for j in colum:
 DoubleArray[i][j]=DoubleList[i][j] 
 
 return DoubleArray
#----------------------------------------------------------------------

def loadtxtdata(filename,delimiter=""):
 """
 #Load Data From Txt-File with delimiter.
 #分隔符默认是:";",",",空格类 (包括	)和自定义的delimiter等
 #Return Value: 二维数值数组(numpy.ndarray)
 #对文本中数据的排列格式要求较高,且不容许出现注释字符,智能化程度较低,但速度较快
 """
 from StringIO import StringIO
 import re
 
 file_handle=open(filename,'r')
 LinesALL=file_handle.read()#读入字符串
 file_handle.close()
 
 DelimiterALL=delimiter+",;"#分隔符
 SpaceString=" "#空格
 for RChar in DelimiterALL:
 LinesALL=LinesALL.replace(RChar,SpaceString)
 
 return numpy.genfromtxt(StringIO(LinesALL))
 
#---------------------------------------------------------------------- 
def savetxtdata(filename, X, fmt='%.8e', delimiter=' ', newline='
'):
 """
 Save Data To Txt-File.
 """
 numpy.savetxt(filename, X, fmt=fmt, delimiter=delimiter, newline=newline) 
 return True
 
#----------------------------------------------------------------------
def dlmwrite(filename, X, fmt='%.8e', delimiter=' ', newline='
'):
 """
 Save Data To Txt-File.
 """
 numpy.savetxt(filename, X, fmt=fmt, delimiter=delimiter, newline=newline) 
 return True
 
#----------------------------------------------------------------------
#测试程序 
#----------------------------------------------------------------------
if __name__ == '__main__':
 #生成随机数
 data=numpy.random.randn(3,4)
 filename='D:/x.txt'
 #写入文件
 dlmwrite(filename,data)
 x=GetDoubleListFromFile(filename)
 print(x)
 print(dlmread(filename))
 y=StringToDoubleArray('79l890joj')
 print(y)
 z=loadtxtdata(filename)
 print(z)