Python data writing and reading basic grammar

# 一维数据的文件写入
f = open("output.txt","w+",encoding="utf-8")
ls = ["日本","英国","巴西"]
f.writelines(' '.join(ls))  # 采用空格分隔形式将数据写入文件  f.write('$'.join(ls))  # 采用特殊符号分隔形式将数据写入文件
f.seek(0)     # 输出显示
for line in f:
    print(line)
f.close()

f = open("output.txt",encoding="utf-8").read()
ls = f.split(" ")
f.close()

# 二维数据的读入
fo = open("biao1.csv").read()
ls = []
for line in fo:
    line = line.replace("\n","")
    ls.append(line.split(","))
fo.cloce()

# 二维数据的写入
ls = [[1,2],[3,4],[5,6]]
f = open("biao1.csv", 'w')
for item in ls:
    f.write(','.join(item) + '\n')
f.close()

ls = [[1,2],[3,4],[5,6]]   # 采用二层循环
for row in ls:
    for column in row:
        print(column)