Python文件路径在pycharm正则表达式混淆中失败

Question

I am a relatively new python user and am getting a funky error using my IDE (pycharm), but not when using the cmd line.

Simply I:

path ='C:\Users\Dell\Downloads\users.dat'

import pandas as pd
unames = ['user_id', 'gender', 'age', 'occupation', 'zip']
users = pd.read_table(path, sep='::', header=None, names=unames)

After which I receive an error that indicates:

ParserWarning: Falling back to the 'python' engine because the 'c' engine does not 
support regex separators; you can avoid this warning by specifying engine='python'.
ParserWarning)

When i input the identical commands into the cmd line and print users the data prints as expected (ie, no errors or anything funky).

EDIT: similarly when I input

ratingsdata ='C:\Users\Dell\Downloads\ratings.dat'

I get a funky IOError: [Errno 22] invalid mode ('r') or filename: Not sure as to why the /r is not ok in a file path... I understand it's regex, but within the quoted lines??

Help!

Answer 1

Looks like on Python 2.7 Pandas just doesn't handle separators that look regexish. The initial "error" can be worked around by adding engine='python' as a named parameter in the call, as suggested in the warning.

Answer 2

Looks like you are attempting to do an exercise from the "Python For Data Analysis" book, I ran into this same issue. All you have to do is use double slashes instead of single slashes like so:

path ='C:\\\\Users\\\\Dell\\\\Downloads\\\\ratings.dat'

Answer 3

如果您正在使用“Python for Data Analysis”并使用PyCharm和Python 3.x，那么可以在此处指定引擎：

ratings = pd.read_table(path + '/ratings.dat', sep='::', header=None, names=rnames, engine='python')

Answer 4

You can add engine = 'python' as a parameter just before the end bracket.

For Example:

ratings = pd.read_table('.../iPythonNotebooks/1mil_movie_reco/ml-1m/ratings.dat', sep='::', header=None, names=rnames, engine = 'python')

Answer 5

I had a similar problem in El Capitan using Python 3. My csv file had a space after all the separators (;) so I used the delimiter '; ' (with a space) in the read_csv call, thus I received the warning.

So I deleted all spaces from the csv file (which was comprised exclusively of integers) and the warning disappeared. Then I added a third column with a header named "some text" without the quotes and data also with spaces. I had to call the column using ['col_name'] so the print function could do its job

dataFile = pd.read_csv("dude.csv", sep = ';')
col2 = dataFile.col2
col3 = dataFile['some text']
print(col2)
print(col3)