pandas.io.parsers.read_fwf

pandas.io.parsers.read_fwf(filepath_or_buffer, colspecs=None, widths=None, **kwds)

Read a table of fixed-width formatted lines into DataFrame

Also supports optionally iterating or breaking of the file into chunks.

Parameters :

filepath_or_buffer : string or file handle / StringIO. The string could be

a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is expected. For instance, a local file could be file ://localhost/path/to/table.csv

colspecs : a list of pairs (tuples), giving the extents

of the fixed-width fields of each line as half-open internals (i.e., [from, to[ ).

widths : a list of field widths, which can be used instead of

‘colspecs’ if the intervals are contiguous.

lineterminator : string (length 1), default None

Character to break file into lines. Only valid with C parser

quotechar : string

The character to used to denote the start and end of a quoted item. Quoted items can include the delimiter and it will be ignored.

quoting : int

Controls whether quotes should be recognized. Values are taken from csv.QUOTE_* values. Acceptable values are 0, 1, 2, and 3 for QUOTE_MINIMAL, QUOTE_ALL, QUOTE_NONE, and QUOTE_NONNUMERIC, respectively.

skipinitialspace : boolean, default False

Skip spaces after delimiter

escapechar : string

dtype : Type name or dict of column -> type

Data type for data or columns. E.g. {‘a’: np.float64, ‘b’: np.int32}

compression : {‘gzip’, ‘bz2’, None}, default None

For on-the-fly decompression of on-disk data

dialect : string or csv.Dialect instance, default None

If None defaults to Excel dialect. Ignored if sep longer than 1 char See csv.Dialect documentation for more details

header : int, default 0 if names parameter not specified,

Row to use for the column labels of the parsed DataFrame. Specify None if there is no header row. Can be a list of integers that specify row locations for a multi-index on the columns E.g. [0,1,3]. Interveaning rows that are not specified (E.g. 2 in this example are skipped)

skiprows : list-like or integer

Row numbers to skip (0-indexed) or number of rows to skip (int) at the start of the file

index_col : int or sequence or False, default None

Column to use as the row labels of the DataFrame. If a sequence is given, a MultiIndex is used. If you have a malformed file with delimiters at the end of each line, you might consider index_col=False to force pandas to _not_ use the first column as the index (row names)

names : array-like

List of column names to use. If file contains no header row, then you should explicitly pass header=None

prefix : string or None (default)

Prefix to add to column numbers when no header, e.g ‘X’ for X0, X1, ...

na_values : list-like or dict, default None

Additional strings to recognize as NA/NaN. If dict passed, specific per-column NA values

true_values : list

Values to consider as True

false_values : list

Values to consider as False

keep_default_na : bool, default True

If na_values are specified and keep_default_na is False the default NaN values are overridden, otherwise they’re appended to

parse_dates : boolean, list of ints or names, list of lists, or dict

If True -> try parsing the index. If [1, 2, 3] -> try parsing columns 1, 2, 3 each as a separate date column. If [[1, 3]] -> combine columns 1 and 3 and parse as a single date column. {‘foo’ : [1, 3]} -> parse columns 1, 3 as date and call result ‘foo’

keep_date_col : boolean, default False

If True and parse_dates specifies combining multiple columns then keep the original columns.

date_parser : function

Function to use for converting a sequence of string columns to an array of datetime instances. The default uses dateutil.parser.parser to do the conversion.

dayfirst : boolean, default False

DD/MM format dates, international and European format

thousands : str, default None

Thousands separator

comment : str, default None

Indicates remainder of line should not be parsed Does not support line commenting (will return empty line)

decimal : str, default ‘.’

Character to recognize as decimal point. E.g. use ‘,’ for European data

nrows : int, default None

Number of rows of file to read. Useful for reading pieces of large files

iterator : boolean, default False

Return TextFileReader object

chunksize : int, default None

Return TextFileReader object for iteration

skipfooter : int, default 0

Number of line at bottom of file to skip

converters : dict. optional

Dict of functions for converting values in certain columns. Keys can either be integers or column labels

verbose : boolean, default False

Indicate number of NA values placed in non-numeric columns

delimiter : string, default None

Alternative argument name for sep. Regular expressions are accepted.

encoding : string, default None

Encoding to use for UTF when reading/writing (ex. ‘utf-8’)

squeeze : boolean, default False

If the parsed data only contains one column then return a Series

na_filter: boolean, default True :

Detect missing value markers (empty strings and the value of na_values). In data without any NAs, passing na_filter=False can improve the performance of reading a large file

usecols : array-like

Return a subset of the columns. Results in much faster parsing time and lower memory usage.

mangle_dupe_cols: boolean, default True :

Duplicate columns will be specified as ‘X.0’...’X.N’, rather than ‘X’...’X’

tupleize_cols: boolean, default False :

Leave a list of tuples on columns as is (default is to convert to a Multi Index on the columns)

Returns :

result : DataFrame or TextParser

Also, ‘delimiter’ is used to specify the filler character of the :

fields if it is not spaces (e.g., ‘~’). :