numpy.savetext()存储csv文件并使用 pandas读取文件时报错

numpy.savetext()存储csv文件并使用 pandas读取文件时报错

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numpy.savetext()方法：

numpy.savetxt(fname, X, fmt=‘%.18e’, delimiter=’ ', newline=‘\n’, header=‘’, footer=‘’, comments='# ', encoding=None)

delimiter是以其为标识来分隔 csv则使用**‘,’**进行分隔

header是写一个列名

encoding是编码方式

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pandas读取csv文件方法：

pandas.read_csv(filepath_or_buffer, ***, sep=_NoDefault.no_default, delimiter=None, header=‘infer’, names=_NoDefault.no_default, index_col=None, usecols=None, dtype=None, engine=None, converters=None, true_values=None, false_values=None, skipinitialspace=False, skiprows=None, skipfooter=0, nrows=None, na_values=None, keep_default_na=True, na_filter=True, verbose=False, skip_blank_lines=True, parse_dates=None, infer_datetime_format=_NoDefault.no_default, keep_date_col=False, date_parser=_NoDefault.no_default, date_format=None, dayfirst=False, cache_dates=True, iterator=False, chunksize=None, compression=‘infer’, thousands=None, decimal=‘.’, lineterminator=None, quotechar=‘"’, quoting=0, doublequote=True, escapechar=None, comment=None, encoding=None, encoding_errors=‘strict’, dialect=None, on_bad_lines=‘error’, delim_whitespace=False, low_memory=True, memory_map=False, float_precision=None, storage_options=None, dtype_backend=_NoDefault.no_default)

这里我们就用到pandas.read_csv(path,header)

path是字符类型的csv文件路径：str, path object or file-like object

header默认为0，即显示第一列为列名

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错误代码：

import pandas as pd
import numpy as np

data = np.random.randint(1, 10, 100)
np.savetxt('demo_csv.csv', data, delimiter=',', fmt='%.3e', header="数据")

indata = pd.read_csv('./demo_csv.csv', header=0)
print(indata)

生成100个1到10随机数，然后使用np.savetext()方法将其存储到demo_csv.csv文件中

再使用pandas读取数据

报错信息：

E:\python\python_sduty_project\venv\Scripts\python.exe E:\python\python_sduty_project\csv文件pandas用法.py 
Traceback (most recent call last):
  File "E:\python\python_sduty_project\csv文件pandas用法.py", line 9, in <module>
    indata = pd.read_csv('./demo_csv.csv', header=0)
  File "E:\python\python_sduty_project\venv\lib\site-packages\pandas\io\parsers\readers.py", line 912, in read_csv
    return _read(filepath_or_buffer, kwds)
  File "E:\python\python_sduty_project\venv\lib\site-packages\pandas\io\parsers\readers.py", line 577, in _read
    parser = TextFileReader(filepath_or_buffer, **kwds)
  File "E:\python\python_sduty_project\venv\lib\site-packages\pandas\io\parsers\readers.py", line 1407, in __init__
    self._engine = self._make_engine(f, self.engine)
  File "E:\python\python_sduty_project\venv\lib\site-packages\pandas\io\parsers\readers.py", line 1679, in _make_engine
    return mapping[engine](f, **self.options)
  File "E:\python\python_sduty_project\venv\lib\site-packages\pandas\io\parsers\c_parser_wrapper.py", line 93, in __init__
    self._reader = parsers.TextReader(src, **kwds)
  File "pandas\_libs\parsers.pyx", line 548, in pandas._libs.parsers.TextReader.__cinit__
  File "pandas\_libs\parsers.pyx", line 637, in pandas._libs.parsers.TextReader._get_header
  File "pandas\_libs\parsers.pyx", line 848, in pandas._libs.parsers.TextReader._tokenize_rows
  File "pandas\_libs\parsers.pyx", line 859, in pandas._libs.parsers.TextReader._check_tokenize_status
  File "pandas\_libs\parsers.pyx", line 2017, in pandas._libs.parsers.raise_parser_error
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xca in position 2: invalid continuation byte

原因：encoding编码错误

import pandas as pd
import numpy as np

data = np.random.randint(1, 10, 100)
np.savetxt('demo_csv.csv', data, delimiter=',', fmt='%.3e', header="数据", encoding='utf-8')

indata = pd.read_csv('./demo_csv.csv', header=0, encoding='utf-8')
print(indata)

改为上面代码即可

运行结果如下：

E:\python\python_sduty_project\venv\Scripts\python.exe E:\python\python_sduty_project\csv文件pandas用法.py 
    # 数据
0    6.0
1    3.0
2    3.0
3    8.0
4    7.0
..   ...
95   3.0
96   8.0
97   4.0
98   8.0
99   8.0

[100 rows x 1 columns]

进程已结束,退出代码0