mindspore.dataset.utils.LineReader
- class mindspore.dataset.utils.LineReader(filename)[source]
Line-based file reader.
Cache the line-based meta data of the file in advance to achieve random-access reading of each file line.
- Parameters
filename (str) – Filename to be read.
- Raises
TypeError – If filename is not of type int.
RuntimeError – If filename does not exist or is not a regular file.
Examples
>>> from mindspore.dataset import LineReader >>> >>> reader = LineReader("/path/to/txt/or/csv/file") >>> # Read the first line of csv file >>> reader.readline(1) >>> # Return the row size in csv file >>> reader.len() >>> # Close the handle >>> reader.close()
- readline(line)[source]
Reads the contents of the specified line.
- Parameters
line (int) – The line number to be read, with a starting line number of 1.
- Returns
str, the contents of the corresponding line, without line break characters.
- Raises
TypeError – If line is not of type int.
ValueError – If line exceeds the total number of lines in the file.