Python IF/ELIF 语句

Question

Okay so for some reason if statement works, but elif doesn't.. not sure why, there's been no syntax or indentation errors, script runs fine however it doesn't use elif as if it wasn't written..

example of code:

try:
    if '120' in resp.read():
        print '120'
        self.write_to_file('120' '\n')
        return True
    elif '130' in resp.read():
        print '130'
        self.write_to_file('130' '\n')
        return True
    else:
        print 'no number'
        return False
except:

Answer 1

You should read a single time and after that do the comparisons with the value that was read:

try:
    value = resp.read()
    if '120' in value:
        print '120'
        self.write_to_file('120' '\n')
        return True
    elif '130' in value:
        print '130'
        self.write_to_file('130' '\n')
        return True
    else:
        print 'no number'
        return False
except:
    # do something here!
    print('error')

Answer 2

Using resp.read() once will read the response completely, so subsequent calls of resp.read() will not yield any output.

You need to store the output in a variable first, and then check on the variable instead of the response again:

response = resp.read()
if '120' in response:
    print '120'
    self.write_to_file('120' '\n')
    return True
elif '130' in response:
    print '130'
    self.write_to_file('130' '\n')
    return True
else:
    print 'no number'
    return False