Create data frame based on rows, which columns meet a certain condition PYTHON

Credit @EdChum

Most certainly, your weight columns is str and in that comparison all your strings are > 0. Turn them to float, int, or something numeric and problem solved.

Hightlight (do this)

result1 = results[result['weight'].astype(float) > 0]

Explanation

Setup 1 (Problem)

text = """source  target weight
     0       0   0.00
     5       1   5.00
     6       2   7.00
     8       3   8.00
     1       4   0.00
     3       5   0.00
     6       6   4.00
     4       7   0.00"""

df = pd.read_csv(StringIO(text), delim_whitespace=1, dtype=str)
#                                                    ^^^^^^^^^
#                                               Create Problem

print df[df.weight > 0]

Looks like:

  source target weight
0      0      0   0.00
1      5      1   5.00
2      6      2   7.00
3      8      3   8.00
4      1      4   0.00
5      3      5   0.00
6      6      6   4.00
7      4      7   0.00

Setup 2 (Solution)

text = """source  target weight
     0       0   0.00
     5       1   5.00
     6       2   7.00
     8       3   8.00
     1       4   0.00
     3       5   0.00
     6       6   4.00
     4       7   0.00"""

df = pd.read_csv(StringIO(text), delim_whitespace=1, dtype=float)
#                                                    ^^^^^^^^^^^
#                                                    Fix Problem

print df[df.weight > 0]

Looks like:

   source  target  weight
1     5.0     1.0     5.0
2     6.0     2.0     7.0
3     8.0     3.0     8.0
6     6.0     6.0     4.0

For your situation, do this:

result1 = results[result['weight'].astype(float) > 0]

Are you just removing zero? If so you can use:

df.loc[~(df==0).all(axis=1)]