1
我用這個基於第二列「ParentID」的python程序分裂出一個非常大的csv。由於大量文件和每個進程限制,我最近更新爲「a」而不是「w」。這樣做我的標題是每次寫入,而不是每個文件中的第一次。Python不寫頭文件
我更新,增加了「write_header = true」和「write_header =假」,但現在它只是寫在第一個文件頭......我有29,000文件
#!/usr/bin/env python3
import binascii
import csv
import os.path
import sys
from tkinter.filedialog import askopenfilename, askdirectory
from tkinter.simpledialog import askinteger
def split_csv_file(f, dst_dir, keyfunc):
csv_reader = csv.reader(f)
header = next(csv_reader)
write_header = True
csv_writers = {}
for row in csv_reader:
k = keyfunc(row)
with open(os.path.join(dst_dir, k), mode='a', newline='') as output:
writer = csv.writer(output)
while write_header:
writer.writerow(header)
write_header = False
csv_writers[k] = writer
csv_writers[k].writerow(row[0:1])
def get_args_from_cli():
input_filename = sys.argv[1]
column = int(sys.argv[2])
dst_dir = sys.argv[3]
return (input_filename, column, dst_dir)
def get_args_from_gui():
input_filename = askopenfilename(
filetypes=(('TXT','.txt'),('CSV', '.csv')),
title='Select CSV Input File')
column = askinteger('Choose Table Column', 'Table column')
dst_dir = askdirectory(title='Select Destination Directory')
return (input_filename, column, dst_dir)
if __name__ == '__main__':
if len(sys.argv) == 1:
input_filename, column, dst_dir = get_args_from_gui()
elif len(sys.argv) == 4:
input_filename, column, dst_dir = get_args_from_cli()
else:
raise Exception("Invalid number of arguments")
with open(input_filename, mode='r', newline='') as f:
split_csv_file(f, dst_dir, lambda r: r[column-1]+'.txt')
# if the column has funky values resulting in invalid filenames
# replace the line from above with:
# split_csv_file(f, dst_dir, lambda r: binascii.b2a_hex(r[column-1].encode('utf-8')).decode('utf-8')+'.csv')
下面是一個例子的文件被分割..
<option value=''>Choose SubGroup</option>, ParentID
<option value='/1990-Accord-DX-Glass-s/37918.htm'>Glass</option>,Accord1990DX422F22A1BodyHardwareBackGlass
<option value='/1990-Accord-DX-Glass-s/37919.htm'>Glass</option>,Accord1990DX422F22A1BodyHardwareBackGlass
<option value='/1990-Accord-DX-Reveal-Moldings-s/69090.htm'>Reveal Moldings</option>,Accord1990DX422F22A1BodyHardwareBackGlass
<option value='/1990-Accord-DX-Reveal-Moldings-s/69091.htm'>Reveal Moldings</option>,Accord1990DX422F22A1BodyHardwareBackGlass
<option value='/1990-Accord-DX-Center-s/10331.htm'>Center</option>,Accord1990DX422F22A1BodyHardwareConsole
<option value='/1990-Accord-DX-Cowl-s/16006.htm'>Cowl</option>,Accord1990DX422F22A1BodyHardwareCowl
<option value='/1990-Accord-DX-Exterior-Trim-s/26889.htm'>Exterior Trim</option>,Accord1990DX422F22A1BodyHardwareFender
<option value='/1990-Accord-DX-Exterior-Trim-s/26890.htm'>Exterior Trim</option>,Accord1990DX422F22A1BodyHardwareFender
我怎樣才能得到頭每寫輸出文件只有一次?
這是有道理的。但是我是新來的蟒蛇,所以我的理解是有點不清楚,所以我只是想你的代碼,並收到此錯誤:回溯(最近通話最後一個): 文件「」,第14行,在split_csv_file ValueError:關閉文件的I/O操作。 在處理上述異常,另一個異常: 回溯(最近通話最後一個): 文件 「」,9號線,在 文件 「」 17行,在split_csv_file AttributeError的:「_csv .writer'對象沒有屬性'close' >>> –
啊,是的;我犯了兩個錯誤:我遺留了'with'語句,忘記單獨存儲文件。稍後會糾正。 –
我看到你的編輯。謝謝。但是這讓我回想起來。我收到了同樣的「太多打開的文件」錯誤,這就是爲什麼我切換到「打開」有沒有一種方法來運行它並關閉文件並重新打開,如果該文本的另一個實例出現。它似乎正在做我所需要的。 –