EOF代表文件结束。嗯,从技术上讲,这不是错误,而是例外。当内置函数之一(最常见的是input())返回文件尾(EOF)而不读取任何数据时,会引发此异常。
在某些特定情况下, Python中出现EOF错误:
- 有时,所有程序尝试做的就是获取某些内容并对其进行修改。但是,当无法获取时,将引发此异常。
- 当输入()函数在两个Python 2.7版和Python 3.6+时,或者当被中断输入()达到出乎意料在Python 2.7文件的末尾。
Python的所有内置异常都继承自BaseException 类或从其中继承的类扩展。此错误的完整异常层次结构为:
BaseException -> Exception -> EOFError
在任何平台上进行编码时,避免PythonEOF的最佳实践是捕获异常,并且我们无需执行任何操作,因此,我们只需在“ except”块中使用关键字“ pass”传递异常即可。
考虑下面的代码,以解决CodeChef K-Foldable String(KFOLD)中的问题:
C++
#Python program for the above question
#Function to reorder the characters
#of the string
def main():
t = int(input())
while t:
# Input variables
n, k = map(int, input().split())
s = input()
ans = ""
# Initialize dictionary
s_dict = dict()
for ch in s:
s_dict[ch] = s_dict.get(ch, 0) + 1
q = n// k
a1 = s_dict['1']// q
a0 = s_dict['0']// q
# Check for valid conditions
if(s_dict['1']%2!=0 or s_dict['0']%2!=0 \\
or s_dict['1']%q!=0 or s_dict['0']%q!=0):
ans = "Impossible"
# Otherwise update the result
else:
st = ('0'*a0) + ('1'*a1)
st = ('1'*a1) + ('0'*a0)
part1 = st + st_rev
ans = part1*(q// 2)
# Print the result for the
# current test case
print(ans)
t -= 1
return
# Driver Code
if __name__=="__main__":
main()
C++
# Python program for the above question
# Function to reorder the characters
#of the string
try : t = int(input())
# Input test cases
while t:
# Input Variables
n, k = map(int, input().split())
s = input()
ans = ""
# Initialize dictionary
s_dict = dict()
for ch in s:
s_dict[ch] = s_dict.get(ch, 0) + 1
q = n// k
a1 = s_dict['1']// q
a0 = s_dict['0']// q
# Check for valid conditions
if(s_dict['1']%2!=0 or s_dict['0']%2!=0 \\
or s_dict['1']%q!=0 or s_dict['0']%q!=0):
ans = "Impossible"
# Otherwise update the result
else:
st = ('0'*a0) + ('1'*a1)
st = ('1'*a1) + ('0'*a0)
part1 = st + st_rev
ans = part1*(q// 2)
# Print the result for the
# current test case
print(ans)
t -= 1
except:
pass
输出:
它给出了EOF错误,如下所示:
上述EOF错误的解决方案是将代码括在try和except块中 并相应地处理异常,下面显示了处理此异常的方法:
C++
# Python program for the above question
# Function to reorder the characters
#of the string
try : t = int(input())
# Input test cases
while t:
# Input Variables
n, k = map(int, input().split())
s = input()
ans = ""
# Initialize dictionary
s_dict = dict()
for ch in s:
s_dict[ch] = s_dict.get(ch, 0) + 1
q = n// k
a1 = s_dict['1']// q
a0 = s_dict['0']// q
# Check for valid conditions
if(s_dict['1']%2!=0 or s_dict['0']%2!=0 \\
or s_dict['1']%q!=0 or s_dict['0']%q!=0):
ans = "Impossible"
# Otherwise update the result
else:
st = ('0'*a0) + ('1'*a1)
st = ('1'*a1) + ('0'*a0)
part1 = st + st_rev
ans = part1*(q// 2)
# Print the result for the
# current test case
print(ans)
t -= 1
except:
pass
输出: