搜索 .txt 中的所有字符串

Question

我正在尝试运行一个程序来查看 .txt 文件，否则取决于内容

我以为会

Searhterms = [A, B]
with('output.txt') as f:

    if ('A' and 'B') in f.read():
        print('mix')
    eLif ('A') in f.read:
        if ('B') not in f.read:
            print('ONLY A')
    elif ('B') in f.read():
        if ('A') not in f.read:
            print('ONLY B') 
    else:
        if ('A' and 'B') not in f.read:
            print('NO AB)

但是，如果 A 和 B 存在，它会起作用，但如果只有一个，它会跳到另一个。越看越糊涂

Answer 1

如评论中所述，f.read() 一次性读取文件的所有内容，因此后续调用 f.read() return 没有数据。您需要将数据存储在变量中。另外，您误解了 and 运算符的工作原理。

with open('output.txt', 'r') as f:
    data = f.read()
    if 'A' in data and 'B' in data:
        print('mix')
    elif 'A' in data:
        print('ONLY A')
    elif 'B' in data:
        print('ONLY B') 
    else:
        print('NO AB)

Answer 2

你最好用这个：

Searhterms = [A, B]  # not sure why you need this

with('output.txt') as fin :  # nice name for the INPUT file, btw
    lines = fin.readlines()

for line in lines :
    if ('A' in line) and ('B' in line):
        print('mix')
    eLif 'A' in line:  # nice uppercase 'L', will puzzle the python
        #if 'B' not in line:    # don't need this
        print('ONLY A')
    elif 'B' in line:
        #if 'A' not in line:    # don't need this
        print('ONLY B') 
    else:
        #if ('A' and 'B') not in f.read:   # this condition is not required
        print('NO AB')

if len(lines) == 0 :
    print('empty file')

Answer 3

我同意@Zabir Al Nazi 的观点。读取 f.read() 清空文件

使用这个

Searhterms = ['A', 'B']

with open('output.txt') as f:
    content = f.read()
    if ('A' and 'B') in content:
        print('mix')
    elif 'A' in content:
        if 'B' not in content:
            print('ONLY A')
    elif 'B' in content:
        if 'A' not in content:
            print('ONLY B')
    else:
        if ('A' and 'B') not in content:
            print('NO AB')

Answer 4

您的代码有点问题。首先，您应该只调用 f.read() 一次。而且你的 if 语句构造错误。

尝试并分析这段代码：

with open('output.txt') as f:
    lines = f.read()

if 'A' in lines and 'B' in lines:
    print('mix')
elif 'A' in lines:
    print('ONLY A')
elif 'B' in lines:
    print('ONLY B')
else:
    print('NO AB')

搜索 .txt 中的所有字符串

Search if all string in .txt

python

if-statement

string-search