I am trying to insert a column called `Price Label` after the `Price` column in my AppleStore apps dataframe by iterating through the dataframe and appending a string ("Free" or "Not Free") to the apps with `price = $0.00.` As such the code I attempted is below

```
for i, row in df.iterrows():
    price = row.Price.replace('$','')
    if price == '0.0':
        row.append("Free")
    else:
        row.append("Non-Free")

df[column].append("price_label")   # in an attempt to add a header to column.

```

But then I'm met with the error message below. Could anyone tell me if there is a special way that pandas can concatenate a string to a data frame series/column? As always, I appreciate the communities help. You guys are the best.

```

TypeError                                 Traceback (most recent call last)
<ipython-input-191-c6a90a84d57b> in <module>
      6         row.append("Free")
      7     else:
----> 8         row.append("Non-Free")
      9 
     10 df.head()

~\anaconda3\lib\site-packages\pandas\core\series.py in append(self, to_append, ignore_index, verify_integrity)
   2580             to_concat = [self, to_append]
   2581         return concat(
-> 2582             to_concat, ignore_index=ignore_index, verify_integrity=verify_integrity
   2583         )
   2584 

~\anaconda3\lib\site-packages\pandas\core\reshape\concat.py in concat(objs, axis, join, ignore_index, keys, levels, names, verify_integrity, sort, copy)
    279         verify_integrity=verify_integrity,
    280         copy=copy,
--> 281         sort=sort,
    282     )
    283 

~\anaconda3\lib\site-packages\pandas\core\reshape\concat.py in __init__(self, objs, axis, join, keys, levels, names, ignore_index, verify_integrity, copy, sort)
    355                     "only Series and DataFrame objs are valid".format(typ=type(obj))
    356                 )
--> 357                 raise TypeError(msg)
    358 
    359             # consolidate

TypeError: cannot concatenate object of type '<class 'str'>'; only Series and DataFrame objs are valid

```