Error in Python editor TypeError: unsupported operand type(s) for +: 'int' and 'str'

TypeError: unsupported operand type(s) for +: 'int' and 'str' I wanted to print out the sequence of 1~9 in the sequence, because the three numbers 1, 2, and 3 are special and need to be typed as 1st, 2nd, and 3rd , all thinking about using "+" to connect symbols. Code: # ordinal countst = [1,2,3,4,5,6,7,8,9] for nums in countst : if nums == ...

TypeError: unsupported operand type(s) for +: ‘int’ and ‘str’

I wanted to print out the sequence of 1~9 in the number sequence, because the three numbers 1, 2, and 3 are special to type 1st, 2nd, and 3rd, so I thought about using "+" to connect symbols.
code:

 # 序数
countst = [1,2,3,4,5,6,7,8,9]
for nums in countst :
    if nums == 1:
        print(nums + 'st')
    elif nums == 2:
        print(nums + 'nd' )
    elif nums == 3:
        print(nums + 'rd' )
    else:
        print(nums + 'th' )

The printed result is:

Traceback (most recent call last):
File "E:/PyCharm/HomeStudy/venv/Include/study511.py", line 5, in <module>
 print(nums + 'st')
TypeError: unsupported operand type(s) for +: 'int' and 'str'

This is a type error, which means that Python cannot recognize the information you use. Python finds that you have used a variable of type int to be associated with a variable of type str. The symbol "+" has the function of addition and connection . Then Python doesn't know how to deal with it . Therefore, you can call the ***str() function***, which tells Python to represent non-string values ​​as strings.
After change:

# 序数
countst = [1,2,3,4,5,6,7,8,9]
for nums in countst :
    if nums == 1:
     print(str(nums) + 'st')
 elif nums == 2:
     print(str(nums) + 'nd' )
 elif nums == 3:
     print(str(nums) + 'rd' )
 else:
     print(str(nums) + 'th' )