Python中将科学计数法（或以e为底的自然对数）字符串转换为float浮点数

没时间完整写，直接上代码吧

# !usr/bin env python
# -*- coding: utf-8 -*-


import re
import math


def ConvertELogStrToValue(eLogStr):
    """
    convert string of natural logarithm base of E to value
    return (convertOK, convertedValue)
    eg:
    input:  -1.1694737e-03
    output: -0.001169

    input:  8.9455025e-04
    output: 0.000895
    """

    (convertOK, convertedValue) = (False, 0.0)
    foundEPower = re.search("(?P<coefficientPart>-?\d+\.\d+)e(?P<ePowerPart>-\d+)", eLogStr, re.I)
    #print "foundEPower=",foundEPower
    if(foundEPower):
        coefficientPart = foundEPower.group("coefficientPart")
        ePowerPart = foundEPower.group("ePowerPart")
        #print "coefficientPart=%s,ePower=%s"%(coefficientPart, ePower)
        coefficientValue = float(coefficientPart)
        ePowerValue = float(ePowerPart)
        #print "coefficientValue=%f,ePowerValue=%f"%(coefficientValue, ePowerValue)
        #math.e= 2.71828182846
        # wholeOrigValue = coefficientValue * math.pow(math.e, ePowerValue)
        wholeOrigValue = coefficientValue * math.pow(10, ePowerValue)

        #print "wholeOrigValue=",wholeOrigValue;

        (convertOK, convertedValue) = (True, wholeOrigValue)
    else:
        (convertOK, convertedValue) = (False, 0.0)

    return (convertOK, convertedValue)

def parseIntEValue(intEValuesStr):
    # print "intEValuesStr=", intEValuesStr
    intEStrList = re.findall("-?\d+\.\d+e-\d+", intEValuesStr)
    # intEStrList = intEValuesStr.split(' ')
    # print "intEStrList=", intEStrList
    for eachIntEStr in intEStrList:
        # intValue = int(eachIntEStr)
        # print "intValue=",intValue
        (convertOK, convertedValue) = ConvertELogStrToValue(eachIntEStr)
        #print "convertOK=%s,convertedValue=%f"%(convertOK, convertedValue)
        print "eachIntEStr=%s,\tconvertedValue=%f" % (eachIntEStr, convertedValue)

# intEValuesStr= 2.1690427e-005 -1.1694737e-003 -6.1193734e-004
# 8.9455025e-004 -8.6277081e-004 -7.2735757e-004
# intEStrList= ['2.1690427e-005', '-1.1694737e-003', '-6.1193734e-004', '8.9455025e-004', '-8.6277081e-004', '-7.2735757e-004']
# eachIntEStr=2.1690427e-005,     convertedValue=0.014615
# eachIntEStr=-1.1694737e-003,    convertedValue=-0.058225
# eachIntEStr=-6.1193734e-004,    convertedValue=-0.112080
# eachIntEStr=8.9455025e-004,     convertedValue=0.163843
# eachIntEStr=-8.6277081e-004,    convertedValue=-0.158022
# eachIntEStr=-7.2735757e-004,    convertedValue=-0.133220

if __name__ == "__main__":
    data_path = "/home/jianjiang/workingdir/CHA/linear-regression/data/data.txt"
    with open(data_path, 'r') as f:
        for line in f.readlines():
            linestr = line.strip()
            # print linestr
            parseIntEValue(linestr)