python中的CSV 工具类

CSV工具类是Python中的自带包，用来解析CSV文件。

1. 实例化一个CSV对象，需要传入一个CSV文件的路径

with open('./case.csv') as casefile

1. csv.DictReader() 将CSV读取成字典的形式

rows2 = csv.DictReader(casefile)
print rows2
# [{'paxID': '111', 'daxID': '222', 'merID': '333'}, {'paxID': '444', 'daxID': '555', 'merID': '666'}]

1. 取一个值

rows2[rowNum][colunmName]
print rows2[2]['paxID']
#444

1. csv.reader() 将CSV读取成list

rows = csv.reader(casefile)
row_list = [row for row in rows]
        print row_list
# [['paxID', 'daxID', 'merID'], ['111', '222', '333'], ['444', '555', '666']]

1. 封装一个csv 工具类

#coding=UTF-8
import csv
import traceback

class CSV:
    def __init__(self,filePath):
        self.filePath = filePath
        self.allRows = None
        try:
            with open(self.filePath) as csvfile:
                rows = csv.DictReader(csvfile)
                self.allRows = [row for row in rows]
        except:
            traceback.print_exc()

    def getAll(self):
        return self.allRows

    def getCell(self, rowNum, colunmName):
        cell = ''
        if rowNum > 0 and colunmName != None:
            try:
                cell = self.allRows[rowNum-1][colunmName]
            except:
                print 'colunmName is inexistent'
        else:
            print 'rowNum should begin from 1 or colunmName is invalid'
        return cell

    #取csv的标题行,字典中的keys
    def getFirstRow(self):
        try:
            dict1 = self.allRows[0]
            keys = dict1.keys()
        except:
            traceback.print_exc()
        return keys

    #取某一纵列的值
    def getColunmName(self, name):
        #创建一个数组，循环大数据，每个字典取Key是name的值，追加到数组中，返回
        result = None
        for d in self.allRows:
            try:
                result.append(d[name])
            except:
                traceback.print_exc()
        return result