How to Read and Write Data in Fixed-Width Format in Pandas
Pandas provides the read_fwf() function to efficiently read data from fixed-width formatted files. These files, unlike comma-separated value (CSV) files, organize data by assigning a specific number of characters to each column. This consistent width allows for structured data storage without delimiters.
The core function for reading these files is pandas.read_fwf(). A critical parameter is filepath_or_buffer, which specifies the path to your fixed-width file. Equally important is colspecs, which defines the starting and ending positions of each column. You can provide a list of tuples, where each tuple represents a column’s start and end indices. Alternatively, you can use ‘infer’, allowing Pandas to attempt to deduce column widths from the file’s content. If you prefer, widths can be used to specify the width of each column, which is more convenient when the columns are contiguous. The delimiter parameter can be used to define filler characters, if the file uses characters other than spaces. The dtype parameter works the same as with other pandas read functions, and allows you to specify the datatypes of the columns. (more…)