74 lines
2.4 KiB
Markdown
74 lines
2.4 KiB
Markdown
---
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title: Converting Integer to String in Python
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---
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## Converting Integer to String in Python
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Unlike many other languages out there, Python does not implicitly typecast integers (or floats) to strings when concatenating with strings. Fortunately, Python has a handy built-in function `str()` which will convert the argument passed in to a string format.
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#### The Wrong Way
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Programmers coming from other languages may attempt to do the following string concatenation which produces an error:
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```py
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age = 18
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string = "Hello, I am " + age + " years old"
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```
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<a href='https://repl.it/JyYH/0' target='_blank' rel='nofollow'>Run code on repl.it</a>
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The error that shows up is
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```
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Traceback (most recent call last):
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File "python", line 3, in <module>
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TypeError: must be str, not int
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```
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`TypeError: must be str, not int` indicates that the integer must first be converted to a string to be concatenated.
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#### The Correct Way
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Simple concatenation example:
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```py
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age = 18
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print("Hello, I am " + str(age) + " years old")
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# Output
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# Hello, I am 18 years old
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```
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<a href='https://repl.it/Jz8Q/0' target='_blank' rel='nofollow'>Run code on repl.it</a>
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Print `1 2 3 4 5 6 7 8 9 10` using a single string
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```py
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result = ""
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for i in range(1, 11):
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result += str(i) + " "
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print(result)
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# Output
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# 1 2 3 4 5 6 7 8 9 10
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```
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<a href='https://repl.it/KBLB/0' target='_blank' rel='nofollow'>Run code on repl.it</a>
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#### Line by Line explanation of the above code
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1. First of all a variable 'result' is assigned to an empty string.
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2. For loop is being used to iterate over a list of numbers.
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3. This list of numbers is generated using the range function.
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4. so range(1,11) is going to generate a list of numbers from 1 to 10.
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5. On each for loop iteration this 'i' variable is going to take up values from 1 to 10.
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6. On first iteration when the variable i=1,then the variable [result=result+str(i)+"(space character)"],str(i) converts the 'i' which is an integer value to a string value.
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7. Since i=1, on the first iteration finally result=1.
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8. And the same process goes on until i=10 and finally after the last iteration result=1 2 3 4 5 6 7 8 9 10.
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9. Therefore when we finally print the result after the for loop the output on the console is '1 2 3 4 5 6 7 8 9 10'.
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#### More Information:
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<a href='https://docs.python.org/3/library/stdtypes.html#str' target='_blank' rel='nofollow'>Official Python documentation for `str()`</a>
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