我有一个 350MB 制表符分隔的文本文件。如果我尝试将其读入内存,则会出现内存不足异常。所以我正在尝试一些类似的事情(即只阅读几列):
import pandas as pd
input_file_and_path = r'C:\Christian\ModellingData\X.txt'
column_names = [
'X1'
# , 'X2
]
raw_data = pd.DataFrame()
for chunk in pd.read_csv(input_file_and_path, names=column_names, chunksize=1000, sep='\t'):
raw_data = pd.concat([raw_data, chunk], ignore_index=True)
print(raw_data.head())
不幸的是,我得到了这个:
Traceback (most recent call last):
File "pandas\_libs\parsers.pyx", line 1134, in pandas._libs.parsers.TextReader._convert_tokens
File "pandas\_libs\parsers.pyx", line 1240, in pandas._libs.parsers.TextReader._convert_with_dtype
File "pandas\_libs\parsers.pyx", line 1256, in pandas._libs.parsers.TextReader._string_convert
File "pandas\_libs\parsers.pyx", line 1494, in pandas._libs.parsers._string_box_utf8
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xae in position 5: invalid start byte
在处理上述异常的过程中,又出现了一个异常:
Traceback (most recent call last):
File "C:/xxxx/EdaDataPrepRange1.py", line 17, in <module>
for chunk in pd.read_csv(input_file_and_path, header=None, names=column_names, chunksize=1000, sep='\t'):
File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\parsers.py", line 1007, in __next__
return self.get_chunk()
File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\parsers.py", line 1070, in get_chunk
return self.read(nrows=size)
File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\parsers.py", line 1036, in read
ret = self._engine.read(nrows)
File "C:\ProgramData\Anaconda3\lib\site-packages\pandas\io\parsers.py", line 1848, in read
data = self._reader.read(nrows)
File "pandas\_libs\parsers.pyx", line 876, in pandas._libs.parsers.TextReader.read
File "pandas\_libs\parsers.pyx", line 903, in pandas._libs.parsers.TextReader._read_low_memory
File "pandas\_libs\parsers.pyx", line 968, in pandas._libs.parsers.TextReader._read_rows
File "pandas\_libs\parsers.pyx", line 1094, in pandas._libs.parsers.TextReader._convert_column_data
File "pandas\_libs\parsers.pyx", line 1141, in pandas._libs.parsers.TextReader._convert_tokens
File "pandas\_libs\parsers.pyx", line 1240, in pandas._libs.parsers.TextReader._convert_with_dtype
File "pandas\_libs\parsers.pyx", line 1256, in pandas._libs.parsers.TextReader._string_convert
File "pandas\_libs\parsers.pyx", line 1494, in pandas._libs.parsers._string_box_utf8
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xae in position 5: invalid start byte
有任何想法吗。顺便说一句,我通常如何处理大文件并估算例如缺失的变量?最终,我需要阅读所有内容来确定,例如,要估算的中位数。