我不明白这个问题
为什么counter可以等于1 i=1（如下面的代码）或可以被i = 0替换并且结果相同？
n = 4
sum = 0 # initialize sum
i = 1 # initialize counter
while i <= n:
sum = sum + i
i = i+1 # update counter
print("The sum is", sum)
最佳答案
# with added line numbers
1. while i < n: # modified this for simplicity.
2. sum = sum + i
3. i = i+1 # update counter
4. print("The sum is", sum)
这是将您的头缠住的执行。
# L1: i=1 n=4 sum=0
# L2: i=1 n=4 sum=1
# L3: i=2 n=4 sum=1
# L1: check i<n - True, 2 is less than 4
# L2: i=2 n=4 sum=3
# L3: i=3 n=4 sum=3
# L1: check i<n - True, 3 is less than 4
# L2: i=3 n=4 sum=6
# L3: i=4 n=4 sum=6
# L1: check i<n - False, 4 not less than 4 ; its equal. condition fail.
# L4: print 6
如果从0开始。
# L1: i=0 n=4 sum=0
# L2: i=0 n=4 sum=0 # see sum is 0+0
# L3: i=1 n=4 sum=0
# L1: check i<n - True, 1 is less than 4
# L2: i=1 n=4 sum=1
# L3: i=2 n=4 sum=1
# L1: check i<n - True, 2 is less than 4
# L2: i=2 n=4 sum=3
# L3: i=3 n=4 sum=3
# L1: check i<n - True, 3 is less than 4
# L2: i=3 n=4 sum=6
# L3: i=4 n=4 sum=6
# L1: check i<n - False, 4 not less than 4 ; its equal. condition fail.
# L4: print 6
当您两者都对比时；您在第二种情况下做了额外的工作迭代。但是，这对
sum没有任何贡献。希望这可以帮助
关于python - 变量初始化-Python，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/47787405/