python 读写csv

def loadlist(filename,colmun1=2, colmun2=5):
    ‘‘‘读取一个坐标文件，返回一个list.
    filename 为文件位置+文件名，例如："./jiaodian.csv
    默认读第2列到第4列
    "‘‘‘
    zblist = []
    with open (filename, ‘r‘) as f:
        reader = csv.reader(f)  #每行是一个list，由他们组成一个大list
        column = [row[colmun1:colmun2] for row in reader]
        for sanlist in column:
            nums = [float(x) for x in sanlist]  #将每行中的每个元素转换为float
            zblist.append(nums) #追加进zblist
        return zblist

    with open("./XXX.csv", "w", newline="") as data:
        csvwriter = csv.writer(data, dialect=("excel"))
        for x in list1:
            csvwriter.writerow(x)
        csvwriter.writerow([])
        csvwriter.writerow(["A(0-0.5)", "B(0.5-1)", "C(1-1.5)", "D(1.5-2)", "E(2-5)", "F(5m以外)",
                            "总点数(不含F)"])
        csvwriter.writerow([A,B,C,D,E,F,A+B+C+D+E])
        csvwriter.writerow([‘%.2f%%‘ %(A/H*100), ‘%.2f%%‘ %(B/H*100),‘%.2f%%‘ %(C/H*100),
                            ‘%.2f%%‘ %(D/H*100),‘%.2f%%‘ %(E/H*100)])