CODEWITHSUNDEEP
pythonpython-3.xpandas
Mitch
Mitch

Reputation: 596

Delete rows based on two conditions

I have a dataframe df that looks like:

    0   1   2   3
0   x   a       
1   x   b       
2   x   c       
3   x   a       
4   x   b       
5   x   c       
6   y   a       
7   y   b       
8   y   c       
9   z   a       
10  z   b       
11  z   c       
12  z   a       
13  z   b       
14  z   c

I want to delete rows where df[1]=="c" AND df[0]==df[0].shift(-1)

However I am not able to combine these 2 conditions. Here is my code:

m1 = (df[df[0].eq(df[0].shift(-1))])
m2 = (df[df[1].eq("x")])

df[~(m1 & m2)]

I get error:

TypeError: unsupported operand type(s) for &: 'str' and 'str'

If I try

df[~(m1 and m2)]

I get error:

ValueError: The truth value of a DataFrame is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

Upvotes: 0

Views: 49

Answers (2)

Valdi_Bo
Valdi_Bo

Reputation: 30971

You should replace AND in your condition with &.

To drop your "not-wanted" rows, retrieve rows not meeting your condition and save under df:

df = df[~((df[1] == 'c') & (df[0] == df[0].shift(-1)))]

The result is:

    0  1
0   x  a
1   x  b
3   x  a
4   x  b
5   x  c
6   y  a
7   y  b
8   y  c
9   z  a
10  z  b
12  z  a
13  z  b
14  z  c

(rows with index == 2 and 11 dropped).

Upvotes: 0

Quang Hoang
Quang Hoang

Reputation: 150735

Try:

m1 = df[0].eq(df[0].shift(-1))
m2 = df[1].eq("x")

df[~(m1 & m2)]

Upvotes: 1

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