Question

我是python的新手，我正在尝试执行以下任务，但我的输出与它应该是的输出不同。任何人都可以帮我解决问题所在吗？感谢您的帮助！

分配：

在第三个程序中，我们来看一下文件内容的分类。在与源代码相同的目录中是一个文件“strings.txt”，它有几行中的随机字符串。这些行可以分为两组：只有字母（az，AZ）和数字（0-9）的那些，以及也有随机特殊字符（？，＆amp;，@，$ ...）的那些。 / p>

创建一个程序，读取文件中的所有行并测试行。如果该行只有字母和/或数字，程序将打印“[line] ok。”。如果该行有特殊字符，程序应打印“[line]无效。”。当程序工作时，它会输出如下内容：

5345m345ö34l was ok.
no2no123non4 was ok.
noq234n5ioqw#% was invalid.
%#""SGMSGSER was invalid.
doghdp5234 was ok.
sg,dermoepm was invalid.
43453-frgsd was invalid.
hsth())) was invalid.
bmepm35wae was ok.
vmopaem2234+0+ was invalid.
gsdm12313 was ok.
bbrbwb55be3"?"#? was invalid.
"?"#%#"!%#"&"?%%"?#?#"?" was invalid.
retrte#%#?% was invalid.
abcdefghijklmnopqrstuvxy was ok.

建议一次读取一行，使用isalmun（）字符串测试对其进行测试，然后从那里继续。还要记住，字符串也可以以换行符（\ n）结束，这是允许的，但如果没有切掉，则无法通过.isalnum（）测试。示例输出

5345m34534l was invalid.
no2no123non4 was ok.
noq234n5ioqw#% was invalid.
%#""SGMSGSER was invalid.
doghdp5234 was ok.
sg,dermoepm was invalid.
43453-frgsd was invalid.
hsth())) was invalid.
bmepm35wae was ok.
vmopaem2234+0+ was invalid.
gsdm12313 was ok.
gswrgsrdgrsgsig45 was ok.
)/(/)(#=%#)%/ was invalid.
++-+-+--+--+-+>-<+-<<_<-+>>++ was invalid.

我的代码是

handle = open("strings.txt","r")
content = handle.read()
content.isalnum()
for i in content:
    if content.isalnum()==True:
        print(content,"was ok")
    else:
        print(content,"was invalid")

handle.close()

我的输出是

5345m34534l
no2no123non4
noq234n5ioqw#%
%#""SGMSGSER
doghdp5234
sg,dermoepm
43453-frgsd
hsth()))
bmepm35wae
vmopaem2234+0+
gsdm12313
gswrgsrdgrsgsig45
)/(/)(#=%#)%/
++-+-+--+--+-+>-<+-<<_<-+>>++. was invalid
5345m34534l
no2no123non4
noq234n5ioqw#%
%#""SGMSGSER
doghdp5234
sg,dermoepm
43453-frgsd
hsth()))
bmepm35wae
vmopaem2234+0+
gsdm12313
gswrgsrdgrsgsig45
)/(/)(#=%#)%/
++-+-+--+--+-+>-<+-<<_<-+>>++. was invalid
5345m34534l
no2no123non4
noq234n5ioqw#%
%#""SGMSGSER
doghdp5234
sg,dermoepm
43453-frgsd
hsth()))
bmepm35wae
vmopaem2234+0+
gsdm12313
gswrgsrdgrsgsig45
)/(/)(#=%#)%/
++-+-+--+--+-+>-<+-<<_<-+>>++. was invalid

# etc ad nauseum...

我做错了什么？

Answer 1

handle = open("strings.txt","r")
content = handle.read()  # <= here you read in the entire file
content.isalnum()
for i in content:      # <= here you iterate over each **character** of the file
    if content.isalnum()==True:
        print(content,"was ok")
               # ^ here you print the entire input file each time
    else:
        print(content,"was invalid")
               # ^ (ditto) which is why you have so much output
handle.close()

相反，请尝试

with open("strings.txt") as inf:
    for line in inf:
        line = line.rstrip()
        if line.isalnum():
            print("{} was ok".format(line))
        else:
            print("{} was invalid".format(line))

Answer 2

我认为输出错误是因为你把整个文件读成一个字符串而且循环遍历文件的所有字符。您的“内容”变量是一个字符串，因此代码不会逐行检查。它会检查整个文件并打印整个文件无效。

我的回答：



file = open("strings.txt","r")
content = file.readlines()
for i in content:
    if i.rstrip().isalnum():
        print(i+" was ok.")
    else:
        print(i+" was invalid.")
file.close()

Answer 3

这是我的作业代码，它给出了所需的输出：

filename="strings.txt"
handle = open("strings.txt","r") #read file
text = handle.readlines() # read lines by lines
for i in text:
    if i.rstrip().isalnum():
        print(i.rstrip()," was ok.")
    else:
        print(i.rstrip()," was invalid.")
handle.close()

Answer 4

handle = open("strings.txt","r")

line = ""
while True:
    line = handle.readline()
    if line == "":
        break
    line = line[:-1]
    if line.isalnum() == False:
        print(line,"was invalid.")
    else:
        print(line,"was ok.")

handle.close()

Answer 5

file = open("strings.txt", "r")
    content = file.readlines()
    file.close()
    for line in content:
        line = line.strip()
        if line.isalnum():
            print(line + " was ok.")
        else:
            print(line + " was invalid.")

python过滤文件内容

5 个答案: