2013-06-03 2 views
36

voglio leggere un file xlsx utilizzando la libreria Pandas di pitone e porta i dati in una tabella di PostgreSQL.
Come leggere un file .xlsx usando la libreria pandas in iPython?

Tutto quello che potevo fare fino ad ora è:

import pandas as pd 
data = pd.ExcelFile("*File Name*") 

Ora so che il passo ottenuto eseguito con successo, ma voglio sapere come posso analizzare il file Excel che si è letto così che posso capire come i dati nell'excel si mappano ai dati nei dati variabili.
ho imparato che i dati è un oggetto dataframe se non sbaglio. Quindi, come faccio a analizzare questo oggetto dataframe per estrarre ogni riga riga per riga.

+6

df = pd.ExcelFile ('File Name') parse ('foglio 1'); vedi documentazione http://pandas.pydata.org/pandas-docs/dev/io.html#excel-files – Jeff

risposta

54

Io di solito creare un dizionario contenente un DataFrame per ogni foglio:

xl_file = pd.ExcelFile(file_name) 

dfs = {sheet_name: xl_file.parse(sheet_name) 
      for sheet_name in xl_file.sheet_names} 

Aggiornamento: Nella versione panda 0.20.0+ (edit: forse 0.19.2 pure) si otterrà questo comportamento in modo più pulito passando sheetname=None a read_excel:

dfs = pd.read_excel(file_name, sheetname=None) 
+0

Grazie Andy. Questo ha funzionato. Ora il mio prossimo passo da qui è quello di scrivere questo in un database postgreSQL. Quale libreria è la migliore da usare? SQLAlchemy? –

+0

Hmmm se lei ha detto [mysql - mi piacerebbe conoscere la risposta] (http://stackoverflow.com/questions/16476413/how-to-insert-pandas-dataframe-via-mysqldb-into-database/16477603#16477603) , postgres * may * funziona in modo simile ... non al 100%. (Sarebbe una buona domanda). –

+0

Ho capito come si fa. Ho usato Sqlalchemy. Avevi ragione, è molto simile a mysql. Ha comportato la creazione di un motore e quindi la raccolta dei metadati e il gioco dei dati. Grazie ancora Andy! :) Apprezzo l'aiuto. –

3

il metodo di dataframe read_excel è come 012.metodo:.

dfs = pd.read_excel(xlsx_file, sheetname="sheet1") 


Help on function read_excel in module pandas.io.excel: 

read_excel(io, sheetname=0, header=0, skiprows=None, skip_footer=0, index_col=None, names=None, parse_cols=None, parse_dates=False, date_parser=None, na_values=None, thousands=None, convert_float=True, has_index_names=None, converters=None, true_values=None, false_values=None, engine=None, squeeze=False, **kwds) 
    Read an Excel table into a pandas DataFrame 

    Parameters 
    ---------- 
    io : string, path object (pathlib.Path or py._path.local.LocalPath), 
     file-like object, pandas ExcelFile, or xlrd workbook. 
     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/workbook.xlsx 
    sheetname : string, int, mixed list of strings/ints, or None, default 0 

     Strings are used for sheet names, Integers are used in zero-indexed 
     sheet positions. 

     Lists of strings/integers are used to request multiple sheets. 

     Specify None to get all sheets. 

     str|int -> DataFrame is returned. 
     list|None -> Dict of DataFrames is returned, with keys representing 
     sheets. 

     Available Cases 

     * Defaults to 0 -> 1st sheet as a DataFrame 
     * 1 -> 2nd sheet as a DataFrame 
     * "Sheet1" -> 1st sheet as a DataFrame 
     * [0,1,"Sheet5"] -> 1st, 2nd & 5th sheet as a dictionary of DataFrames 
     * None -> All sheets as a dictionary of DataFrames 

    header : int, list of ints, default 0 
     Row (0-indexed) to use for the column labels of the parsed 
     DataFrame. If a list of integers is passed those row positions will 
     be combined into a ``MultiIndex`` 
    skiprows : list-like 
     Rows to skip at the beginning (0-indexed) 
    skip_footer : int, default 0 
     Rows at the end to skip (0-indexed) 
    index_col : int, list of ints, default None 
     Column (0-indexed) to use as the row labels of the DataFrame. 
     Pass None if there is no such column. If a list is passed, 
     those columns will be combined into a ``MultiIndex`` 
    names : array-like, default None 
     List of column names to use. If file contains no header row, 
     then you should explicitly pass header=None 
    converters : dict, default None 
     Dict of functions for converting values in certain columns. Keys can 
     either be integers or column labels, values are functions that take one 
     input argument, the Excel cell content, and return the transformed 
     content. 
    true_values : list, default None 
     Values to consider as True 

     .. versionadded:: 0.19.0 

    false_values : list, default None 
     Values to consider as False 

     .. versionadded:: 0.19.0 

    parse_cols : int or list, default None 
     * If None then parse all columns, 
     * If int then indicates last column to be parsed 
     * If list of ints then indicates list of column numbers to be parsed 
     * If string then indicates comma separated list of column names and 
      column ranges (e.g. "A:E" or "A,C,E:F") 
    squeeze : boolean, default False 
     If the parsed data only contains one column then return a Series 
    na_values : scalar, str, list-like, or dict, default None 
     Additional strings to recognize as NA/NaN. If dict passed, specific 
     per-column NA values. By default the following values are interpreted 
     as NaN: '', '#N/A', '#N/A N/A', '#NA', '-1.#IND', '-1.#QNAN', '-NaN', '-nan', 
    '1.#IND', '1.#QNAN', 'N/A', 'NA', 'NULL', 'NaN', 'nan'. 
    thousands : str, default None 
     Thousands separator for parsing string columns to numeric. Note that 
     this parameter is only necessary for columns stored as TEXT in Excel, 
     any numeric columns will automatically be parsed, regardless of display 
     format. 
    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. 
    verbose : boolean, default False 
     Indicate number of NA values placed in non-numeric columns 
    engine: string, default None 
     If io is not a buffer or path, this must be set to identify io. 
     Acceptable values are None or xlrd 
    convert_float : boolean, default True 
     convert integral floats to int (i.e., 1.0 --> 1). If False, all numeric 
     data will be read in as floats: Excel stores all numbers as floats 
     internally 
    has_index_names : boolean, default None 
     DEPRECATED: for version 0.17+ index names will be automatically 
     inferred based on index_col. To read Excel output from 0.16.2 and 
     prior that had saved index names, use True. 

    Returns 
    ------- 
    parsed : DataFrame or Dict of DataFrames 
     DataFrame from the passed in Excel file. See notes in sheetname 
     argument for more information on when a Dict of Dataframes is returned.