Error in seaborn plot Horizontal orientation requires numeric `x` variable

I'm not familiar with seaborn, but I'd guess from the error that there's at least one text value inside the Synergy_percent field that is encouraging the rest of the values to text. Either that, or spaces in the input file are messing up the parsing of the columns.

Very quickly because I'm not around.

I think I know what's going on, but don't have enough time to figure the df. The key thing is seaborn needs to know where columns are x and which are y ... within the data frame . This information appears missing and the OP used y='title', x='title without reference to the dataframe. I'm pretty certain thats the bug here.

import seaborn as sns
import matplotlib.pyplot as plt

plot = sns.boxplot(
    color='white',
    y=synergy_df["Synergy_percent"], 
    x=synergy_df["Min PPI distance"] 
);
plt.show()

Alternative, which seems more what the OP wants ...

import seaborn as sns
import matplotlib.pyplot as plt

plot = sns.boxplot(
    color='white',
    # use your orientation command here
    x=synergy_df["Synergy_percent"], 
    y=synergy_df["Min PPI distance"] 
);
plt.show()

Blurb Normally the x-axis is the discrete boundary whilst the y-axis is continuous. In you example the x-axis feels like the continuous variable and you are producing a rotated boxplot - thats perfectly fine and seabourn will do that however its good to get it working first before rotating the axes.

Final The orientation of the dataframe might possibly be an issue, not sure unless its tried.

If there's a formatting issue the only trick I know is

 plot = sis.boxplot(
 .... # same old
 dodge=True,
 );

I don't know beyond, e.g. imposing percentile ranges onto a boxplot.