Collating data based on a parameter in python - python-2.7

Question

I have the following type of data:
Col1 Col2 Col3
heyA 123 ABC
heyB 456 VCV
heyA 123 SDF
heyA 123 ABC
I want to collate them such that
The output should be:
Col1 Col2 Col3
heyA 123 ABC,SDF
heyB 456 VCV
Please suggest me ways of doing this. Thanks a lot in advance!
I have tried:
for i in Col1:
for k in Col1:
if i==k:
//dosome
else:
//dosomethingelse
but this isnt giving me the desired result. It is matching the same entry with itself and hence, the incorrect result.

Answer 1

According to your question, I assume that you're a beginner in python. So, my answer here will be boring to the pros.
First, you need to install pandas which is a cool python module that deals with datasets.
Second, you need to custom your data points and make them look like the following dictionary (I will leave this part to you):
d = {"Col1": ["heyA", "heyB", "heyA", "heyA"],
"Col2": [123, 456, 123, 123],
"Col3": ["ABC", "VCV", "SDF", "ABC"]}
Now, the fun part begins!
We will use a function from pandas module, this function is called group_by(). This function groups the data based on a specified column values. So, let's try it out and group our data accoring to the first two columns which are Col1 and Col2:
>>> import pandas as pd
>>>
>>> df = pd.DataFrame(d)
>>> grouped = df.groupby( ["Col1", "Col2"] )
>>> grouped
<pandas.core.groupby.DataFrameGroupBy object at 0x000000000AB9A6A0>
>>> grouped.groups
{('heyA', 123L): Int64Index([0, 2, 3], dtype='int64'),
('heyB', 456L): Int64Index([1], dtype='int64')}
As you can see, now we have two groups ('heyA', 123L) and ('heyB', 456L).
Now, let's use the groupby object and apply a function to it, we will apply the set casting to remove duplicated values. Then, we will use the function reset_index() to reset the indices.
>>> grouped['Col3'].apply(set).reset_index()
Col1 Col2 Col3
0 heyA 123 {SDF, ABC}
1 heyB 456 {VCV}
If you're concerned about the {} brackets, you can run the following line instead:
>>> grouped['Col3'].apply(set).apply(list).reset_index()
Col1 Col2 Col3
0 heyA 123 [SDF, ABC]
1 heyB 456 [VCV]