字符串轉換整數python

Unlike many other programming languages out there, Python does not implicitly typecast integers (or floats) to strings when you concatenate them to strings.

與現有的許多其他編程語言不同，Python在將整數連接到字符串時不會隱式地將整數(或浮點數)類型轉換為字符串。

Fortunately, Python has a handy built-in function str() which will convert the argument passed in to a string format.

幸運的是，Python有一個方便的內置函數str() ，它將把傳入的參數轉換為字符串格式。

在Python中將字符串轉換為整數的錯誤方法 (The Wrong Way to Convert a String to an Integer in Python)

Programmers coming from other programming languages may attempt to do the following string concatenation, which will produce an error:

來自其他編程語言的程序員可能會嘗試執行以下字符串連接，這將產生錯誤：

age = 18string = "Hello, I am " + age + " years old"

You can run this code on repl.it.

您可以在repl.it上運行此代碼 。

The error that shows up is:

顯示的錯誤是：

Traceback (most recent call last):File "python", line 3, in <module>
TypeError: must be str, not int

Here, TypeError: must be str, not int indicates that the integer must first be converted to a string before it can be concatenated.

在這里， TypeError: must be str, not int ，該整數必須先轉換為字符串才能連接。

在Python中將字符串轉換為整數的正確方法 (The Correct Way to Convert a String to an Integer in Python )

Here's a simple concatenation example:

這是一個簡單的串聯示例：

age = 18print("Hello, I am " + str(age) + " years old")# Output
# Hello, I am 18 years old

You can run this code on repl.it.

您可以在repl.it上運行此代碼 。

Here's how to print 1 2 3 4 5 6 7 8 9 10 using a single string:

以下是使用單個字符串打印1 2 3 4 5 6 7 8 9 10方法：

result = ""for i in range(1, 11):result += str(i) + " "print(result)# Output
# 1 2 3 4 5 6 7 8 9 10

You can run the code on repl.it.

您可以在repl.it上運行代碼 。

以下是上述代碼的工作原理的逐行說明： (Here's a line-by-Line explanation of how the above code works:)

1. First of all a variable ‘result’ is assigned to an empty string.
   首先，將變量“結果”分配給一個空字符串。
2. The for loop is being used to iterate over a list of numbers.
   for循環用于遍歷數字列表。
3. This list of numbers is generated using the range function.
   此數字列表是使用范圍函數生成的。
4. so range(1,11) is going to generate a list of numbers from 1 to 10.
   因此range(1,11)將生成一個從1到10的數字列表。
5. On each for loop iteration this ‘i’ variable is going to take up values from 1 to 10.
   在每個for循環迭代中，此“ i”變量將采用從1到10的值。
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.
   在第一次迭代中，當變量i = 1時，然后變量[result = result + str(i)+“(space character)”]，str(i)將整數值“ i”轉換為字符串值。
7. Since i=1, on the first iteration finally result=1.
   由于i = 1，因此在第一次迭代中最終結果= 1。
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.
   直到i = 10，最后一次迭代結果= 1 2 3 4 5 6 7 8 9 10。
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’.
   因此，當我們最終在for循環之后打印結果時，控制臺上的輸出為'1 2 3 4 5 6 7 8 9 10'。

I hope you've found this helpful. Happy coding.

希望對您有所幫助。 快樂的編碼。

翻譯自: https://www.freecodecamp.org/news/python-string-to-int-how-to-convert-a-string-to-an-integer-in-python/

字符串轉換整數python