9、Find substring inside String

9-1 Function 1: Double loop string

假设要从主串 s = "goodgoogle" 中找到 t = "google" 子串

def main():
    s = "goodgoogle"
    t = "google"
    isFind = 0

    for i in range(0,len(s)-len(t)+1):
        if s[i] == t[0]:
            jc = 0
            for j in range(0,len(t)):
                if s[i+j] != t[j]:
                    break
                jc = j

        if jc == len(t)-1:
            isFind = 1 
    print(isFind)

s[i+j] != t[j]: 不同了就break

if s[i+j] != t[j]:
    break

9-2 Function 2: Python inner function: index()

def main():
    s = "goodgoogle"
    t = "google"
    try:
        if s.index(t) > 0:
            print('Found')
    except ValueError:
        print('Not foud')

if __name__ == '__main__':
    main()

output:
Found

9-3 Function 2: Python inner function: find()

s = "goodgoogle"
t = "google"
print(s.find(t))