Pandas Merge returning NaN?

Question

I have 2 dataframes:

df1=

State           Code
Alabama         AL
Alaska          AK
American Samoa  AS
Arizona         AZ
Arkansas        AR

df2=

State            PREVAILING_WAGE
CALIFORNIA       102170.0
DELAWARE         97531.0
SOUTH CAROLINA   96824.0
WASHINGTON       89586.0
OREGON           88234.0

Now when I try to merge both if them using:

df1.merge(df2,left_on='State',right_on='State',how='left')

I get NaN values in the merged table like this:

State          PREVAILING_WAGE   Code
CALIFORNIA     102170.0          NaN
DELAWARE       97531.0           NaN
SOUTH CAROLINA 96824.0           NaN
WASHINGTON     89586.0           NaN
OREGON         88234.0           NaN

I checked the dtypes too, and both of them are objects or str. How do I solve this?

Thanks

EDIT: The dataframes contain all states names, so they have common stuff to match.

Answer 1

If you use a left join, if df2.State value does not exist in df1.State, it will return NaN in Code, meaning there is not a match.

I will check if there is any extra white space after each string in the State columns, and make sure all values are upper cases and converted to str.