Python替换方法

Question

我写了下面的代码，但replace方法不起作用

代码：

courses = input("Please enter the courses you have taken previously with letter grades: ")
courses.replace("M","X")
print(courses)

请以字母成绩输入您之前所修的课程：

MATH101:A;SPS101:B;CS201:B+;HIST191:D;CS204:F;CS210:S:
MATH101:A;SPS101:B;CS201:B+;HIST191:D;CS204:F;CS210:S:

Answer 1

courses = courses.replace("M","X")

正如12944qwerty所说，你需要重新分配课程

Answer 2

replace不会在适当的位置改变字符串str.replace()

courses = courses.replace("M", "X")

Answer 3

replace方法不会替换原始字符串中的文本，而是返回一个新字符串。 你需要做的是-

courses = courses.replace("M", "X")
print(courses)