Created
May 1, 2014 11:42
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Python: Class to parse a CSV file using the parser in another gist. Instantiate this object with a) the path + filename, b) delimiters (multiple accepted) and c) quote characters and it returns a file object that can be iterated over and read normally.
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| class CSVObject(object): | |
| """ | |
| This class instantiates a file object as an interable. It means that | |
| CSV files can be read more efficiently than reading the entire data | |
| into memory. | |
| """ | |
| def __init__(self, fileName, delims, quotes): | |
| self.fileName = fileName | |
| self.delims = delims | |
| self.quotes = quotes | |
| self.fin = open(fileName, 'r') | |
| def __iter__(self): | |
| return self | |
| def next(self): | |
| line = self.fin.next() | |
| return self.ParseLine(line) | |
| def ParseLine(self, line): | |
| """ | |
| Parses a line of CSV text into components. This attempts to | |
| be a proper parser that can cope with multiple delimiters. | |
| """ | |
| inQuote = False # flag for being 'within' quotes | |
| token = '' # current token | |
| tokens = [] # list of tokens | |
| for char in line: | |
| if inQuote: # so if we're in the middle of a quote... | |
| if char == inQuoteChar: # ...and have a matching quote character... | |
| tokens.append(token) # add the token to list (ignore quote character) | |
| token = '' # and begin new token | |
| inQuote = False # flag that we're not in a quote any more | |
| else: # But if char is a non-matching quote... | |
| token += char # ...just add to token | |
| elif char in self.delims: # or if char is a delimiter... | |
| if len(token) > 0: # ...and token is worth recording... | |
| tokens.append(token) # add token to list | |
| token = '' # and begin new token | |
| else: # if token has 0 length and no content... | |
| pass # ...adjacent delimiters so do nothing | |
| elif char in self.quotes: # But if char is a quote... | |
| inQuoteChar = char # record it to check for matching quote later | |
| inQuote = True # and flag that we're in a quotation | |
| else: # And if char is anything else... | |
| token += char # add to token | |
| if len(token) > 0: # Check if last item is worth recording (len > 0) | |
| tokens.append(token) # add to list of tokens | |
| return tokens # return list of tokens | |
| if __name__ == '__main__': | |
| fName = '/Users/alansalmoni/00_test.csv' | |
| delims = ',; ' | |
| quotes = '"' + "'" | |
| CSVFile = CSVObject(fName, delims, quotes) | |
| for line in CSVFile: | |
| print line |
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