python 字典写入csv python csv 字典

在日常数据分析时最常打交道的是csv文件和list,dict类型。涉及到的主要需求有：

1. 将一个二重列表[[],[]]写入到csv文件中
2. 从文本文件中读取返回为列表
3. 将一字典写入到csv文件中
4. 从csv文件中读取一个字典
5. 从csv文件中读取一个计数字典

实现如下：

# 功能：将一个二重列表写入到csv文件中
# 输入：文件名称，数据列表
def createListCSV(fileName="", dataList=[]):
    with open(fileName, "wb") as csvFile:
        csvWriter = csv.writer(csvFile)
        for data in dataList:
            csvWriter.writerow(data)
        csvFile.close

# 功能：从文本文件中读取返回为列表的形式
# 输入：文件名称，分隔符（默认,）
def readListCSV(fileName="", splitsymbol=","):
    dataList = []
    with open(fileName, "r") as csvFile:
        dataLine = csvFile.readline().strip("\n")
        while dataLine != "":
            tmpList = dataLine.split(splitsymbol)
            dataList.append(tmpList)
            dataLine = csvFile.readline().strip("\n")
        csvFile.close()
    return dataList

# 功能：将一字典写入到csv文件中
# 输入：文件名称，数据字典
def createDictCSV(fileName="", dataDict={}):
    with open(fileName, "wb") as csvFile:
        csvWriter = csv.writer(csvFile)
        for k,v in dataDict.iteritems():
            csvWriter.writerow([k,v])
        csvFile.close()

# 功能：从csv文件中读取一个字典
# 输入：文件名称，keyIndex,valueIndex
def readDictCSV(fileName="", keyIndex=0, valueIndex=1):
    dataDict = {}
    with open(fileName, "r") as csvFile:
        dataLine = csvFile.readline().strip("\n")
        while dataLine != "":
            tmpList = dataLine.split(splitsymbol)
            dataDict[tmpList[keyIndex]] = tmpList[valueIndex]
            dataLine = csvFile.readline().strip("\n")
        csvFile.close()
    return dataDict

# 功能：从csv文件中读取一个计数字典
# 输入：文件名称，keyIndex
def readDictCSV(fileName="", keyIndex=0):
    dataDict = {}
    with open(fileName, "r") as csvFile:
        dataLine = csvFile.readline().strip("\n")
        while dataLine != "":
            tmpList = dataLine.split(splitsymbol)
            if dataDict.get(tmpList[keyIndex]) == None:
                dataDict[tmpList[keyIndex]] = 0
            dataDict[tmpList[keyIndex]] = dataDict.get(tmpList[keyIndex]) + 1
            dataLine = csvFile.readline().strip("\n")
        csvFile.close()
    return dataDict