CODEWITHSUNDEEP
pythonclass
Matt
Matt

Reputation: 23

Why is this invalid syntax? (Class function)

The code I am trying to enter (python) looks like this:

class RainfallTable:
    def _init_ (self, njrainfall.txt):
        self.njrainfall.txt = open(njrainfall.txt, 'r')
    def close(self):
        if self.t:
            self.t.close()
            self.t = None

I am trying to get this class to simply open a file called njrainfall.txt, but I get the following error message when I do so:

  File "3Homework.py", line 2
def _init_ (self, njrainfall.txt):
                            ^

What am I doing wrong?

Upvotes: 0

Views: 3953

Answers (4)

Ming Jin
Ming Jin

Reputation: 331

Remove the fullstop here 

self.njrainfall.txt
to something else.

Like

self.njrainfall

Upvotes: 0

carnicer
carnicer

Reputation: 523

It looks like you are confused with strings, parameter/variable names, and class objects.

The dot you are using in what must be a variable name (njrainfall.txt) looks like either a string with an actual file name, or an object attribute.

As other people have pointed out already, you shall not use a dot in a variable / parameter name.

You should instead do use (I have added a try..except to handle the case in which the passed filename does not exist):

class RainfallTable:
  def _init_ (self, sRainFallFilename):
    try:
      self.rainfallFile = open(sRainFallFilename, 'r')
    except:
      self.rainfallFile = None
      print "file %s does not exist" % sRainFallFilename

  def close(self):
    if not self.rainfallFile == None :
        self.rainfallFile.close()
        self.rainfallFile = None

Notice I have also changed the close() method to use the same attribute as in init()

Then you can call the class like:

RainFallTable myRainFallTable( "NJ.txt" )
...
myRainFallTable.close()

Upvotes: 0

be_good_do_good
be_good_do_good

Reputation: 4441

Function/constructor should have only variables as input

You can pass text file name along with path to that init function

Better you pass text file with absolute path

class RainfallTable:
    def _init_ (self, textfile):
        self.t = open(textfile, 'r')
    def close(self):
        if self.t:
            self.t.close()
            self.t = None

Call it as RainfallTable('njrainfall.txt')

Upvotes: 0

Andrew Li
Andrew Li

Reputation: 57934

You've got a . in your variable names, which is invalid syntax for python. Remove those in your njrainfall.txt variables. A good substitute would be njrainfall_file or something similar. Secondly, the init functions is written with two underscores, like so:

def __init__(self, njrainfall_file):

Here some code:

class RainfallTable:
    def __init__(self, njrainfall_file):
        self.njrainfall_file = open(njrainfall_file, 'r')
    def close(self):
        if self.t:
            self.t.close()
            self.t = None

Make sure to pass njrainfall_file as a string of filename!

Upvotes: 3

Related Questions