读写字符串或文本文件中的数据

用python和numpy处理数据次数比较多,写了几个小函数,可以方便地读写数据:

# -*- 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('\n')#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\t)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\t)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='\n'):
    """
    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='\n'):
    """
    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)

我只在python2.7中试过,如果要在python3.x中使用,可自行测试.

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