def check_province_code(province, country): 
  num = len(province) 
   
  while num <3: 
    province = ''.join([str(0),province]) 
    num = num +1 
   
  return country + province 

check_province_code('ab', '001') 
--------------------------------------------------------------------------- 
TypeError                 Traceback (most recent call last) 
<ipython-input-44-02ec8a351cce> in <module>() 
----> 1 check_province_code('ab', '001') 
 
<ipython-input-43-12db968aa80a> in check_province_code(province, country) 
   3  
   4   while num <3: 
----> 5     province = ''.join([str(0),province]) 
   6     num = num +1 
   7  
 
TypeError: 'str' object is not callable  

>>> str(1233) 
--------------------------------------------------------------------------- 
TypeError                 Traceback (most recent call last) 
<ipython-input-45-afcef5460e92> in <module>() 
----> 1 str(1233) 
 
TypeError: 'str' object is not callable  

str = '123'