如何将第一个操作的输出发送到第二个操作的输入？

Question

我试图找到一种方法，可以将在crop_rows调用的crop_rows的输出发送到delete_Apps直接调用的delete_Apps的输入中，但是我不确定要喂什么。 另外，我是否需要删除：

file_obj.close()

来自crop_rows函数，以便我的脚本继续通过这两个函数运行？

import os, csv, sys, Tkinter, tkFileDialog as fd


# stop tinker shell from opening as only needed for file dialog

root = Tkinter.Tk()
root.withdraw()


#crop_rows deletes the extra info automatically generated in the Waders report 

def crop_rows(in_path):
    # read file into memory
    file_obj = open(in_path, 'rb')
    reader = csv.reader(file_obj, delimiter='\t')
    data = []
    for row in reader:
        if not row or not any(row):
            break #stop at empty row
        else:
            data.append(row)
    file_obj.close()

    print 'Found', len(data), 'rows of data without empty lines.'
    conf = raw_input('delete remaining lines? (Y|N): ').upper()[0]

    if conf == 'Y':
        # write data to file
        file_obj = open(in_path, 'wb')
        writer = csv.writer(file_obj)
        writer.writerows(data)
        file_obj.close



#delete_Apps deletes and leads that are currently Applicants in gHire as their Status

def delete_Apps(in_path):
    # read file into memory
    file_obj = open(in_path, 'rb')
    reader = csv.reader(file_obj, delimiter='\t')
    data = []
    for row in reader:
        if 'Applicant' not in row:
            data.append(row)
    file_obj.close()

    print 'Found', len(data), 'Leads with Applicant in gHire as Status.'
    conf = raw_input('delete these leads? (Y|N): ').upper()[0]

    if conf == 'Y':
        # write data to file
        file_obj = open(in_path, 'wb')
        writer = csv.writer(file_obj)
        writer.writerows(data)
        file_obj.close


def main():
    in_path = None
    prog_name = sys.argv[0]

    # check if in_path are inlcuded as cmd line args...
    if len(sys.argv) > 1:
        in_path = sys.argv[1]
        if not os.path.exists(in_path):
            print 'Usage:', prog_name, '[file_path>]'
            print 'cannot find the file provided for file_path:\n', in_path
            sys.exit("Error - invalid excel_file_path arg")
    else:
        try:
            # set current working directory to user's my documents folder
            os.chdir(os.path.join(os.getenv('userprofile'),'documents'))
        except:
            pass

    # ask user for path to file...
    while not in_path:
        print "Please select the file to read data from ..."
        try:
            in_path = fd.askopenfilename()
        except:
            print 'Error selecting file.'
        if not in_path:
            cont = raw_input('Do you want to continue? (Y|N): ').upper()[0]
            if cont == 'N':
                sys.exit("Error - unable to select input file")

    crop_rows(in_path)


    delete_Apps(in_path)




if __name__ == '__main__':
    main()

Answer 1

将crop_rows更改为生成器函数（请参阅https://wiki.python.org/moin/Generators ），然后在delete_Apps中使用它。

Answer 2

1. 分别阅读.csv文件
2. 更改crop_rows ，使其将行作为输入并返回新数据
3. 然后更改delete_Apps以接受行输入并返回修改后的数据
4. 最后编写.csv文件

然后，您可以简单地嵌套对函数的调用，如下所示：

def read_input_file(in_path):
    # use with not to worry about closing the file
    with open(in_path, 'rb') as file_obj:
        reader = csv.reader(file_obj, delimiter='\t')
        return list(reader)

def crop_rows(input_rows):
    data = []
    for row in input_rows:
        if not row or not any(row):
            break #stop at empty row
        else:
            data.append(row)

    print 'Found', len(data), 'rows of data without empty lines.'
    conf = raw_input('delete remaining lines? (Y|N): ').upper()[0]

    if conf == 'Y':
        return data       
    else:
        # return unmodified data
        return input_rows

def delete_Apps(input_rows):
    data = []
    for row in input_rows:
        if 'Applicant' not in row:
            data.append(row)

    print 'Found', len(data), 'Leads with Applicant in gHire as Status.'
    conf = raw_input('delete these leads? (Y|N): ').upper()[0]

    if conf == 'Y':
        return data
    else:
        return input_rows

def write_output_file(data, out_path):
    wirg open(out_path, 'wb') as file_obj:
    writer = csv.writer(file_obj)
    writer.writerows(data)
    file_obj.close()

最后的电话：

file_path='/tmp/whatever.csv'
write_output_file(delete_Apps(crop_rows(read_input_file(file_path)), file_path)