如何使用iPython中的pandas库读取.xlsx文件?


103

我想使用python的Pandas库读取.xlsx文件,并将数据移植到postgreSQL表中。

到目前为止,我所能做的就是:

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

现在,我知道该步骤已成功执行,但是我想知道如何解析已读取的excel文件,以便可以了解excel中的数据如何映射到变量数据中的数据。
我了解到,如果我没有记错的话,数据就是一个Dataframe对象。因此,我如何解析此dataframe对象以逐行提取每一行。


8
df = pd.ExcelFile('文件名').parse('工作表1'); 请参阅docs pandas.pydata.org/pandas-docs/dev/io.html#excel-files
Jeff

Answers:


162

我通常会DataFrame为每个工作表创建一个包含的字典:

xl_file = pd.ExcelFile(file_name)

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

更新:在pandas 0.21.0+版本中,您可以通过传递sheet_name=Noneread_excel

dfs = pd.read_excel(file_name, sheet_name=None)

在0.20及sheetname更低版本中,它是而不是sheet_name(现在已弃用,而转而支持上述内容):

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

谢谢安迪。这工作了。现在,我的下一步是将其写入postgreSQL数据库。哪个库最适合使用?SQLAlchemy?
Sabareesh Kappagantu 2013年

嗯,如果您说的是mysql-我知道答案,postgres 可能也可以类似地工作……虽然不是100%。(将是一个很好的问题。)
Andy Hayden 2013年

我知道怎么做。我使用了Sqlalchemy。您是对的,它与mysql非常相似。它涉及创建引擎,然后收集元数据并处理数据。再次感谢安迪!:)感谢帮助。
Sabareesh Kappagantu 2013年

1
pandas.DataFrame.to_sql可能会有帮助。为了阅读,您可以使用dp.py返回的Pandas DataFrame对象。
FinnÅrupNielsen

我正在尝试实现类似的目标,但是通过使用2个xlsx excel文件制作一个数据框,我想知道您是否可以看一下并协助我继续进行操作,我通过创建另一个问题来寻求帮助stackoverflow.com / questions / 16888888 /… @AndyHayden
Deepak M

25
from pandas import read_excel
# find your sheet name at the bottom left of your excel file and assign 
# it to my_sheet 
my_sheet = 'Sheet1' # change it to your sheet name
file_name = 'products_and_categories.xlsx' # change it to the name of your excel file
df = read_excel(file_name, sheet_name = my_sheet)
print(df.head()) # shows headers with top 5 rows

11

DataFrame的read_excel方法类似于read_csv方法:

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.

6

如果您不知道或无法打开excel文件以签入ubuntu(在我的情况下为Python 3.6.7,ubuntu 18.04),则可以使用参数index_col(index_col = 0)来代替工作表名称。第一张)

import pandas as pd
file_name = 'some_data_file.xlsx' 
df = pd.read_excel(file_name, index_col=0)
print(df.head()) # print the first 5 rows

1
您还可以使用sheet_name=0或命名表而不是0
Plajerity

1
是的,它有效。但是它需要依赖项xlrd。(pip3.7.4.exe在Windows上安装xlrd)
哈里

5

将电子表格文件名分配给 file

加载电子表格

打印工作表名称

通过名称将表加载到DataFrame中:df1

file = 'example.xlsx'
xl = pd.ExcelFile(file)
print(xl.sheet_names)
df1 = xl.parse('Sheet1')

2

如果在使用read_excel()函数打开的文件上使用open(),请确保将其添加rb到打开函数中,以避免编码错误

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