Question

尝试从.txt文件读取一行，然后根据该行的内容编写if语句。我写了我认为应该起作用的内容，它可以打印出该行，但是if语句可以打印出“此行为假”

select gameid,palyerid, 
max(case when event_desc='Shot' then count end) as shot,
max(case when event_desc='Miss' then count end) as Miss,
max(case when event_desc='Rebound' then count end) as Rebound,
max(case when event_desc='Foul' then count end) as Foul,
max(case when event_desc='Assist' then count end) as Assist,
------
from table_name group by  gameid,palyerid

结果：

是

该行为False

Answer 1

这里是一个简短的解释：

import linecache

test = open('test.txt', 'w+')
test.write('Test\n')
test.write('True\n')
test.close()
read = linecache.getline('test.txt', 2)
# At this moment read has 'True\n' as value
print(read)
# However print formats the output with the special character. Hence your print 
will have a line return try print(read+read) to see

if read == 'True': # This evaluate to False
    print("The line is True")
else: #Well this is an else, you should avoid doing so if you have a binary condition. Writing elif read == 'False' is not too bad
    print('The line is False')

此外，我的答案是指出为什么它没有按照您的怀疑行为。请参阅有关str.strip（）的文档：https://docs.python.org/2/library/stdtypes.html#str.strip

Answer 2

问题（如第一个评论所建议，是换行符。在[2]中：阅读出[2]：“真\ n”

要解决此问题，您可以：如果read.rstrip（）=='真'： print（“这条线是真实的”）其他： print（'该行为假'）

此外，仅当您由于文件太大而遇到性能问题时，才使用线缓存。否则使用 open（'test.txt'）。readlines（）[-1]

获取最后一行

从.txt文件读取特定行

2 个答案: