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Files: sorer -- main method to parse and store data from file sor.py -- class definition for SoR, which is a data structure containing a 2D list of data, a schema detailing what datatype each column is, and a number of columns. It also has various methods to be performed on the SoR class. util.py -- document containing various util methods to be used that aren't specific to the SoR class

Part 1: Determine Schema First, we read the first 500 lines of the file (or the entire file, if the file is less than 500 lines). From here, we determine the schema. This is done in the method generateSchema() as part of the SoR class

We parse each line of the file into a list of the elements in it, discarding any line with invalid elements. We determine an invalid element to be any element inside of a "<>" that has spaces in it without starting and ending with a double quote.

We create a list composed of each parsed line of the file. We now have a 2D list where each row was each line from the file, and each column is a column of one particular datatype.

Then, we determine the datatype contained in each colum. We do this in the function getType. To determine the datatype of the column, we look at all of the elements in the column one by one. First, we check to see if these elements are booleans. If we find an element with an integer value, this column must not be booleans. If we find an element with a float value, this column must not be booleans or integers. If we find an element that isn't a boolean, integer, or float, it must be a column of strings.

Once we have identified a type for each column, we save this in the SoR field schema.

Part 2: Store Data Then we store the data from the file we read in. We do this in the method generateData() in the SoR class. We start reading from either the beginning of the file or the offset provided to us with the flag -start. If the numerical value for -start is not equal to zero, we discard the first line of the file, assuming that the line wasn't complete. We stop reading when we get to the end of the file or when we have read the number of bytes provided to us with the flag -len. In the case that we have read all the bytes we are allowed to read and we still have not reached the end of the file, we discard the last line we read, assuming it is incomplete.

We parse each row as we read it into a list of its elements, and we then store that list of elements in the field data in our SoR class. Now, our data field is a 2D list representation of the section of the file that we read in.

If, when we parse the row, we determine that the row is missing elements (ie. the length of the parsed row is less than the length of the file schema (stored by the field numColumns in SoR)), we add empty strings at the end of the list to make it the same length as numColumns and represent missing elements.

Part 3: Print Data Option 1: print_col_type

We take the index of the column from the arguments, and call the method getColumnType() from the SoR class, which returns the type (one of: INT, BOOL, FLOAT, STRING) of the column as a string. This is then printed.

Option 2: print_col_idx

We get the element at the specified row and column location with getElement() from the SoR class, make sure it matches the type we have determined the column to be (checked with getColumnType() and compareType() from the util.py file), and then we print the element.

Option 3: is_missing_idx We get the element at the specified row and column location as we do for print_col_idx. Then, we check if this element is an empty string. If so, we print 1 for True, since the element is missing. Otherwise, we print 0 for false since the element is not missing.