BUG: merge fails to rename when name already exists

[jseabold]

Trying to merge a bunch of files in a loop. I realize there's a better way to do this and a workaround, but it took me a second to realize what was going on here.

w = pd.DataFrame(np.random.random((4,2)), columns=["x", "y"]) 
x = pd.DataFrame(np.random.random((4,2)), columns=["x", "y"])
y = pd.DataFrame(np.random.random((4,2)), columns=["x", "y"])
z = pd.DataFrame(np.random.random((4,2)), columns=["x", "y"])

dta = x.merge(y, left_index=True, right_index=True).merge(z, left_index=True, right_index=True, how="outer")

dta.merge(w, left_index=True, right_index=True)

[jreback]

would this work for you?

dups, which make certain operations a bit odd

In [22]: concat([w,x,y,z],axis=1)
Out[22]: 
          x         y         x         y         x         y         x         y
0 -0.563069 -0.961155  0.431668  0.878735 -0.388918  0.922276 -0.519004  0.801015
1 -1.562759 -0.273918 -1.019135 -1.245221 -0.428684 -1.153576  0.573085  1.766883
2  0.538920 -0.196340  0.947958 -1.089876  0.681975 -0.176980  0.572076  0.932001
3 -0.583187  0.041399  0.420735 -1.839026 -0.827691 -0.996057 -1.050309 -0.832534

or

In [23]: concat([w,x,y,z],keys=['w','x','y','z'],axis=1)
Out[23]: 
          w                   x                   y                   z          
          x         y         x         y         x         y         x         y
0 -0.563069 -0.961155  0.431668  0.878735 -0.388918  0.922276 -0.519004  0.801015
1 -1.562759 -0.273918 -1.019135 -1.245221 -0.428684 -1.153576  0.573085  1.766883
2  0.538920 -0.196340  0.947958 -1.089876  0.681975 -0.176980  0.572076  0.932001
3 -0.583187  0.041399  0.420735 -1.839026 -0.827691 -0.996057 -1.050309 -0.832534

[jseabold]

Yeah, that's nice. It won't work for me (I have a terrible situation) and ended up going a completely different route. Just found the error message to be pretty cryptic until I thought about it.

[jreback]

ok....that's an easy fix then