Working with dataframes

[rotemkat]

i 3 "datasets":

Output:
genes_mouse_human = data frame where one of the columns is "gene symbol_human" and another is "gene symbol mouse"
data =  data frame where one of the columns is "gene symbol"
genes_list_mouse = a series of gene names (i created it from filtering another data frame with some codition)

what I'm trying to do now is:

Output:
run through genes_list_mouse
for each item - 
1) find the gene symbol mouse, and find the relevant human symbol 
2) find the row in "data" that holds this gene
3) do some calculations on this row

currently I'm having troubles completing 1 and 2.
this is what i tried to do:

for i in genes_list_mouse:
    gene_human = genes_mouse_human [genes_mouse_human ['Symbol_mouse']==i]['Symbol_human'].astype("string")
    ind = data.where(data['gene symbol']==gene_human.values)

i get the following error:

Error:
ValueError: ('Lengths must match to compare', (20530,), (1,))

can you please help me understand why it's not working and what is the best way to do these simple steps?
thanks!!!!