先說下:所謂的大文件并不是壓縮文件有多大,幾十兆的文件而是解壓后幾百兆。其中就遇到解壓不成功的情況.、讀小文件時成功,大文件時失敗等
def unzip_to_txt_plus(zipfilename): zfile = zipfile.ZipFile(zipfilename, 'r') for filename in zfile.namelist(): data = zfile.read(filename) # data = data.decode('gbk').encode('utf-8') data = data.decode('gbk', 'ignore').encode('utf-8') file = open(filename, 'w+b') file.write(data) file.close()if __name__ == '__main__': zipfilename = "E://share//python_excel//zip_to_database//20171025.zip" unzip_to_txt_plus(zipfilename)注意參數:‘ignore' ,因為默認是嚴格編碼,如果不加這個參數就會報錯。
因為該函數已經把文件編成utf-8 所以后面讀取文件時成功,下面貼出讀取大文件代碼(忽略數據庫相關)
# - coding: utf-8 -import csvimport linecacheimport xlrdimport MySQLdbdef txt_todatabase(filename, linenum): # with open(filename, "r", encoding="gbk") as csvfile: # Read = csv.reader(csvfile) # count =0 # for i in Read: # # print(i) # count += 1 # # print('hello') # print(count) count = linecache.getline(filename, linenum) print(count) # with open("new20171028.csv", "w", newline="") as datacsv: # # dialect為打開csv文件的方式,默認是excel,delimiter="/t"參數指寫入的時候的分隔符 # csvwriter = csv.writer(datacsv, dialect=("excel")) # # csv文件插入一行數據,把下面列表中的每一項放入一個單元格(可以用循環插入多行) # csvwriter.writerow(["A", "B", "C", "D"])def bigtxt_read(filename): with open(filename, 'r', encoding='utf-8') as data: count =0 while 1: count += 1 line = data.readline() if 1000000 == count: print(line) if not line: break print(count)if __name__ == '__main__': filename = '20171025.txt' txt_todatabase(filename, 1000000) bigtxt_read(filename)經過對比,發現兩個速度基本一樣快。兩百萬行的數據是沒壓力的。
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