这个程序应该读取一个名为year的类别的输入文件。因此，如果用户键入198，则输出应该给出其中包含198的所有年份，例如1981,1982，...等。 但是，产量也增加了199
Sierra Leone WB_LI 0 Africa 1992
Sierra Leone WB_LI 0 Africa 1993
Sierra Leone WB_LI 0 Africa 1994
Sierra Leone WB_LI 0 Africa 1995
Sierra Leone WB_LI 0 Africa 1996
Sierra Leone WB_LI 0 Africa 1997
该文件的每一行都包含以下字段，其中字段之间有一个空格： 国家（50个字符） 收入等级（6个字符） 接种百分比（3个字符） 地区（25个字符） 年（4个字符）。所以，我总共有92个字符，我会在88个病房中查看每个字符，并在一年中将它们与字符匹配以找到所需的年份。我想我的逻辑中可能有一些错误，并且还将199视为一个实例。我不应该使用列表或元组。只需提交。
以下是我对我的代码所做的事情：
def main():
#checks if the input file exists or not.
#If the file exists, then the program breaks out of the loop and
#moves on. Otherwise, the program halts with an IOError message.
while True:
try:
input_file=open('measles.txt','r')
break
except IOError:
print("Error opening file:",input_file)
break
f2=input("What is the name of the output file? ")
#checks if the output file exists or not.
#If the file exists, then the program breaks out of the loop and
#moves on. Otherwise, the program halts with an IOError message.
while True:
try:
output_file=open(f2,'w')
break
except IOError:
print("Error opening file:",output_file)
break
#for loop prints all lines of the input file to the output file.
year=str(input('Input year: '))
line=input_file.readline().strip()
while line!="":
for line in input_file:
if year==line[88:92]:
output_file.write(line)
elif year==line[88:91]:
output_file.write(line)
elif year==line[88:90]:
output_file.write(line)
elif year==line[88:89]:
output_file.write(line)
elif year.lower()=="all" or year=="''" or year=='""':
print(line)
line=input_file.readline().strip()
input_file.close()
output_file.close()
main()
有人可以看看我的代码并指出问题吗？谢谢 以下是我正在处理的文件的几行。
Afghanistan WB_LI 11 Eastern Mediterranean 1980
Afghanistan WB_LI 0 Eastern Mediterranean 1981
Afghanistan WB_LI 8 Eastern Mediterranean 1982
Afghanistan WB_LI 9 Eastern Mediterranean 1983
Afghanistan WB_LI 14 Eastern Mediterranean 1984
Afghanistan WB_LI 14 Eastern Mediterranean 1985
Afghanistan WB_LI 14 Eastern Mediterranean 1986
Afghanistan WB_LI 31 Eastern Mediterranean 1987
Afghanistan WB_LI 34 Eastern Mediterranean 1988
Afghanistan WB_LI 22 Eastern Mediterranean 1989
Afghanistan WB_LI 20 Eastern Mediterranean 1990
Afghanistan WB_LI 19 Eastern Mediterranean 1991
Afghanistan WB_LI 22 Eastern Mediterranean 1992
Afghanistan WB_LI 25 Eastern Mediterranean 1993
Afghanistan WB_LI 40 Eastern Mediterranean 1994
Afghanistan WB_LI 41 Eastern Mediterranean 1995
Afghanistan WB_LI 42 Eastern Mediterranean 1996
Afghanistan WB_LI 38 Eastern Mediterranean 1997
Afghanistan WB_LI 31 Eastern Mediterranean 1998
Afghanistan WB_LI 31 Eastern Mediterranean 1999
Afghanistan WB_LI 27 Eastern Mediterranean 2000
Afghanistan WB_LI 37 Eastern Mediterranean 2001
Afghanistan WB_LI 35 Eastern Mediterranean 2002
Afghanistan WB_LI 39 Eastern Mediterranean 2003
Afghanistan WB_LI 48 Eastern Mediterranean 2004
Afghanistan WB_LI 50 Eastern Mediterranean 2005
Afghanistan WB_LI 53 Eastern Mediterranean 2006
Afghanistan WB_LI 55 Eastern Mediterranean 2007
Afghanistan WB_LI 59 Eastern Mediterranean 2008
Afghanistan WB_LI 60 Eastern Mediterranean 2009
Afghanistan WB_LI 62 Eastern Mediterranean 2010
Afghanistan WB_LI 65 Eastern Mediterranean 2011
Afghanistan WB_LI 68 Eastern Mediterranean 2012
Albania WB_LMI 90 Europe 1980
Albania WB_LMI 90 Europe 1981
Albania WB_LMI 93 Europe 1982
Albania WB_LMI 96 Europe 1983
Albania WB_LMI 96 Europe 1984
Albania WB_LMI 96 Europe 1985
Albania WB_LMI 96 Europe 1986
Albania WB_LMI 96 Europe 1987
Albania WB_LMI 96 Europe 1988
Albania WB_LMI 96 Europe 1989
Albania WB_LMI 88 Europe 1990
Albania WB_LMI 80 Europe 1991
Albania WB_LMI 87 Europe 1992
Albania WB_LMI 76 Europe 1993
Albania WB_LMI 90 Europe 1994
Albania WB_LMI 91 Europe 1995
Albania WB_LMI 92 Europe 1996
Albania WB_LMI 95 Europe 1997
Albania WB_LMI 89 Europe 1998
Albania WB_LMI 85 Europe 1999
Albania WB_LMI 95 Europe 2000
Albania WB_LMI 95 Europe 2001
Albania WB_LMI 96 Europe 2002
Albania WB_LMI 93 Europe 2003
答案 0 :(得分：1)
正如我在评论中提到的，您提供的输入与您的描述不符。您的代码显示从索引year开始的88字段，但您提供的输入只有44个字符长。我会从那里开始。
编辑：这是我编写程序的方式，因为你不能使用任何容器。
def filter_results(input_file, output_file, year):
for line in input_file:
if not line: continue # skips if the line is blank
if year == '' or line[88:92].startswith(year) or year.lower() == 'all':
output_file.write(line+"\n")
def main():
year = input("Give me a year: ")
try: infile = open('measles.txt','r')
except IOError: print("Error opening file: measles.txt")
try: outfile = open(input("Name of output file?"),'w')
except IOError: print("Error opening output file")
try: infile,outfile
except NameError: raise IOError("One of the files could not be opened")
filter_results(infile,outfile,year)
outfile.close()
infile.close()
main()
那就是说，我首先阅读文件并将其写入dict。类似的东西：
lines = list()
with open('path/to/input_file') as input_file:
for line in input_file:
lines.append(
{"country":line[0:51].strip(),
"income":line[52:58].strip(),
"vaccinated":line[59:62].strip(),
"region":line[63:88].strip(),
"year":line[89:93].strip()}
# I may have screwed up that string splicing -- do one and doublecheck
year = input("Enter a four-digit year (or part thereof): ")
filtered_list = [line for line in lines if line['year'].startswith(year)]
现有代码中也存在一些问题。
while True:
try:
input_file = open("measles.txt")
break # ?
except IOError:
print("Error opening file:",input_file)
break # ?
如果我们在一次迭代后总是破坏，为什么我们在这里循环？在没有while True的情况下放弃try:except和break。如果您需要在异常时暂停程序，那么只需执行except IOError: raise