Importing text file : No Columns to parse from file

Question

I am trying to take input from sys.stdin. This is a map reducer program for hadoop. Input file is in txt form. Preview of the data set: ``` 196 242 3 881250949 186 302 3 891717742 22 377 1 878887116 244 51 2 880606923 166 346 1 886397596 298 474 4 884182806 115 265 2 881171488 253 465 5 891628467 305 451 3 886324817 6 86 3 883603013 62 257 2 879372434 286 1014 5 879781125 200 222 5 876042340 210 40 3 891035994 224 29 3 888104457 303 785 3 879485318 122 387 5 879270459 194 274 2 879539794 291 1042 4 874834944 ``` Code that I have been trying - ``` import sys df = pd.read_csv(sys.stdin,error_bad_lines=False) ``` I have also tried with `delimiter = 	, header=False,defining column name` Nothing seems to work, the error I am getting is this error: ``` [root@sandbox lab]# cat /root/lab/u.data | python /root/lab/mid-1-mapper.py |python /root/lab/mid-1-reducer.py Traceback (most recent call last): File "/root/lab/mid-1-reducer.py", line 8, in <module> df = pd.read_csv(sys.stdin,delimiter='	…

Accepted Answer

Using try and except just lets you continue in spite of errors and handle them. It won't magically fix your errors.

`read_csv` expects `csv` files, which your input is obviously not. A quick look into the documentation:

delim_whitespace : boolean, default False

Specifies whether or not whitespace (e.g. ' ' or ' ') will be used as the sep. Equivalent to setting sep='+s'. If this option is set to True, nothing should be passed in for the delimiter parameter.

This seems like the right argument. Use

```
pandas.read_csv(filepath_or_buffer, delim_whitespace=True).
```

Using `delimiter='	'` should also work, unless the tabs are expanded (replaced by spaces). As we can't really tell, `delim_whitespace` seems to be the better option.

If this doesn't help, just print out your `sys.stdin` to check if you properly pass the text.

Edit: I just saw that you use

```
cat /root/lab/u.data | python /root/lab/mid-1-mapper.py |python /root/lab/mid-1-reducer.py
```

Is this intended, this way `mid-1-reducer.py` processes the output of `mid-1-mapper.py`. If you want to process the content of the file `u.data` consider reading the file and not `sys.stdin`.

Importing text file : No Columns to parse from file

Solution

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