Day 1

学习内容：

使用csv模块和pandas模块读取csv文件并将文件内容写入输出文件。

#csv模块import sysimport csvinput_file = sys.argv[1]output_file = sys.argv[2]with open(input_file,'r',newline='') as csv_in_file:    with open(output_file,'w',newline='') as csv_out_file:        filereader = csv.reader(csv_in_file,delimiter=',')        filewriter = csv.writer(csv_out_file,delimiter=',')        for row_list in filereader:            print (row_list)            filewriter.writerow(row_list)

#pandas模块import sysimport pandas as pdinput_file = sys.argv[1]output_file = sys.argv[2]data_frame = pd.read_csv(input_file)print(data_frame)data_frame.to_csv(output_file,index=False)

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使用特定条件筛选csv文件中特定的行，并将筛选的行写入输出文件。

#csv模块import sysimport csvinput_file = sys.argv[1]output_file = sys.argv[2]with open(input_file,'r',newline='') as csv_in_file:    with open(output_file,'w',newline='') as csv_out_file:        filereader = csv.reader(csv_in_file)        filewriter = csv.writer(csv_out_file)        header = next(filereader)        filewriter.writerow(header)        for row_list in filereader:            supplier = str(row_list[0]).strip()            cost = str(row_list[3]).strip('$').replace(',','')            if supplier == 'Supplier Z' or float(cost) > 600.0:                filewriter.writerow(row_list)

#pandas模块import sysimport pandas as pdinput_file = sys.argv[1]output_file = sys.argv[2]data_frame = pd.read_csv(input_file)data_frame['Cost'] = data_frame['Cost'].str.strip('$').astype(float)data_frame_value_meets_condition = data_frame.loc[(data_frame['Supplier Name']\.str.contains('Z')) | (data_frame['Cost'] > 600.0),:]data_frame_value_meets_condition.to_csv(output_file,index=Falsed)