| def to_csv Found at: pandas.core.generic def to_csv(
self,
path_or_buf:Optional[FilePathOrBuffer]=None,
sep:str=",",
na_rep:str="",
float_format:Optional[str]=None,
columns:Optional[Sequence[Label]]=None,
header:Union[bool_tList[str]]=True,
index:bool_t=True,
index_label:Optional[Union[bool_tstrSequence[Label]]]
=None,
mode:str="w",
encoding:Optional[str]=None,
compression:Optional[Union[strMapping[strstr]]]="infer",
quoting:Optional[int]=None,
quotechar:str='"',
line_terminator:Optional[str]=None,
chunksize:Optional[int]=None,
date_format:Optional[str]=None,
doublequote:bool_t=True,
escapechar:Optional[str]=None,
decimal:Optional[str]=".",
errors:str="strict")->
Optional[str]:
r"""
Write object to a comma-separated values (csv) file.
.. versionchanged:: 0.24.0
The order of arguments for Series was changed. | 將物件寫入逗號分隔值(csv)檔案。 |
| Parameters
----------
path_or_buf : str or file handle, default None. File path or object, if None is provided the result is returned as a string. If a file object is passed it should be opened with `newline=''`, disabling universal newlines.
.. versionchanged:: 0.24.0
Was previously named "path" for Series.
sep : str, default ','. String of length 1. Field delimiter for the output file.
na_rep : str, default ''. Missing data representation.
float_format : str, default None. Format string for floating point numbers.
columns : sequence, optional. Columns to write.
header : bool or list of str, default True.Write out the column names. If a list of strings is given it is assumed to be aliases for the column names.
.. versionchanged:: 0.24.0
Previously defaulted to False for Series.
index : bool, default True. Write row names (index).
index_label : str or sequence, or False, default None. Column label for index column(s) if desired. If None is given, and `header` and `index` are True, then the index names are used. A sequence should be given if the object uses MultiIndex. If False do not print fields for index names. Use index_label=False for easier importing in R.
mode : str.Python write mode, default 'w'.
encoding : str, optional.A string representing the encoding to use in the output file, defaults to 'utf-8'.
compression : str or dict, default 'infer'. If str, represents compression mode. If dict, value at 'method' is the compression mode. Compression mode may be any of the following
possible values: {'infer', 'gzip', 'bz2', 'zip', 'xz', None}. If compression mode is 'infer' and `path_or_buf` is path-like, then detect compression mode from the following extensions: '. gz', '.bz2', '.zip' or '.xz'. (otherwise no compression). If dict given and mode is one of {'zip', 'gzip', 'bz2'}, or inferred as one of the above, other entries passed as additional compression options. .. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode and other entries as additional compression options if compression mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is supported for compression modes 'gzip' and 'bz2' as well as 'zip'. | 引數
----------
path_or_buf : str或file handle，預設無。檔案路徑或物件，如果沒有提供，結果將作為字串返回。如果一個檔案物件被傳遞，它應該被開啟' newline= " '，禁用通用換行。
. .versionchanged: 0.24.0
之前被命名為「path」系列。
sep : str，預設為'，'。長度為1的字串。輸出檔案的欄位分隔符。
na_rep : str，預設值"。缺失的資料表示。
float_format : str，預設沒有。浮點數的格式字串。
columns : 序列，可選。列寫。
header : bool或str列表，預設為True。寫出列名。如果給定了字串列表，則假定它是列名的別名。
. .versionchanged: 0.24.0
以前對於級數預設為False。
index : bool，預設為True。寫行名稱(索引)。
iindex_label : str或序列，或False，預設無。如果需要，用於索引列的列標籤。如果沒有給出，並且' header '和' index '為真，則使用索引名。如果物件使用多索引，則應該給出一個序列。如果為False，不要列印索引名稱的欄位。使用index_label=False在R中更容易匯入。
mode : str.Python編寫模式，預設為「w」。
encoding : str，可選。表示要在輸出檔案中使用的編碼的字串，預設為「utf-8」。
compression : str或dict，預設為'infer'。如果為str，表示壓縮模式。如果是dict, value at 'method'是壓縮模式。壓縮模式可以是下列任何一種
possible values: {'infer', 'gzip', 'bz2', 'zip', 'xz', None}.。如果壓縮模式是'infer'，而' path_or_buf '是類似路徑的，那麼從以下擴充套件中檢測壓縮模式:'。 '. gz', '.bz2', '.zip' or '.xz'. 。(否則不壓縮)。如果dict given和mode是{'zip'、'gzip'、'bz2'}或推斷為上述選項之一，則其他項作為附加壓縮選項傳遞。 . .versionchanged: 1.0.0
如果壓縮模式是「zip」，則可以使用關鍵的「方法」作為壓縮模式，其他條目作為附加的壓縮選項。
. .versionchanged: 1.1.0
壓縮模式「gzip」和「bz2」以及「zip」支援將壓縮選項作為鍵在dict中傳遞。 |
| quoting : optional constant from csv module. Defaults to csv.QUOTE_MINIMAL. If you have set a `float_format` then floats are converted to strings and thus csv. QUOTE_NONNUMERIC will treat them as non-numeric.
quotechar : str, default '\"'. String of length 1. Character used to quote fields.
line_terminator : str, optional. The newline character or character sequence to use in the output file. Defaults to `os.linesep`, which depends on the OS in which this method is called ('\n' for linux, '\r\n' for Windows, i.e.).
.. versionchanged:: 0.24.0
chunksize : int or None. Rows to write at a time.
date_format : str, default None.Format string for datetime objects.
doublequote : bool, default True. Control quoting of `quotechar` inside a field.
escapechar : str, default None. String of length 1. Character used to escape `sep` and `quotechar` when appropriate.
decimal : str, default '.'. Character recognized as decimal separator. E.g. use ',' for European data.
errors : str, default 'strict'.Specifies how encoding and decoding errors are to be handled. See the errors argument for :func:`open` for a full list of options.
.. versionadded:: 1.1.0 | quoting : csv模組中的可選常數。預設為csv.QUOTE_MINIMAL。如果你設定了一個' float_format '，那麼float就會被轉換為字串，從而轉換為csv。QUOTE_NONNUMERIC將把它們視為非數值。
quoting : str，預設為'\"'。長度為1的字串。用於參照欄位的字元。
line_terminator : str，可選。輸出檔案中要使用的換行字元或字元序列。預設的作業系統。linesep '，它取決於呼叫該方法的作業系統(例如，linux是'\n'， Windows是'\r\n')。
. .versionchanged: 0.24.0
chunksize : int或None。每次要寫入的行。
date_format : str，預設無。日期時間物件的格式字串。
doublequote :bool，預設為True。控制欄位內參照「quotechar」。
escapechar : str，預設無。長度為1的字串。在適當的時候，字元用於跳脫' sep '和' quotechar '。
decimal : str，預設為'.'。可識別為十進位制分隔符的字元。例如，使用「，」表示歐洲資料。
errors : str，預設為「strict」。指定如何處理編碼和解碼錯誤。檢視:func: ' open '的錯誤引數以獲得選項的完整列表。
. .versionadded: 1.1.0 |
| Examples
--------
>>> df = pd.DataFrame({'name': ['Raphael', 'Donatello'],
... 'mask': ['red', 'purple'],
... 'weapon': ['sai', 'bo staff']})
>>> df.to_csv(index=False)
'name,mask,weapon\nRaphael,red,sai\nDonatello,purple,bo
staff\n'
Create 'out.zip' containing 'out.csv'
>>> compression_opts = dict(method='zip',
... archive_name='out.csv') # doctest: +SKIP
>>> df.to_csv('out.zip', index=False,
... compression=compression_opts) # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
from pandas.io.formats.csvs import CSVFormatter
formatter = CSVFormatter(
df,
path_or_buf,
line_terminator=line_terminator,
sep=sep,
encoding=encoding,
errors=errors,
compression=compression,
quoting=quoting,
na_rep=na_rep,
float_format=float_format,
cols=columns,
header=header,
index=index,
index_label=index_label,
mode=mode,
chunksize=chunksize,
quotechar=quotechar,
date_format=date_format,
doublequote=doublequote,
escapechar=escapechar,
decimal=decimal)
formatter.save()
if path_or_buf is None:
return formatter.path_or_buf.getvalue()
return None # ----------------------------------------------------------------------
# Lookup Caching | |