-->字典用於以鍵：值對的形式儲存資料值。
-->字典是一個有序的、可更改的、不允許重複的集合。
-->在字典中，每個元素都可以透過它們的鍵來訪問，而不是透過索引。
-->如果字典不包含該鍵，則輸出將為「KeyError」。
範例：
thisdict = {
"brand": "Ford",
"model": "Mustang",
"year": 1964
}
student = {"name":"raja", "class":5}
print(thisdict)
print(student)
輸出：
{'brand': 'Ford', 'model': 'Mustang', 'year': 1964}
{'name': 'raja', 'class': 5}
練習：使用巢狀循環找出字串中的字元
1.找出字串中每個字母的頻率
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
print(key, count)
j+=1
輸出：
g 1 u 2 r 2 p 1 a 3 s 1 n 2
*2。字母只出現一次 *
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count == 1 and key!='*':
print(key, count)
j+=1
輸出：
g 1 p 1 s 1
3。最常見的字母
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count != 1 and key!='*':
print(key, count)
j+=1
輸出：
u 2 r 2 a 3 n 2
4。第一個不重複的字母
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count == 1 and key!='*':
print(key, count)
break
j+=1
輸出：
g 1
5。第一個重複的字母
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count != 1 and key!='*':
print(key, count)
break
j+=1
6。最後一個不重複的字母
last = ' '
last_count = 0
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count == 1 and key!='*':
last = key
last_count = count
#print(key, count)
j+=1
print(last, last_count)
輸出：
s 1
7。最後重複的字母
last = ' '
last_count = 0
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count != 1 and key!='*':
last = key
last_count = count
#print(key, count)
j+=1
print(last, last_count)
輸出：
n 2
8。最常見的字母
s = 'guruprasanna'
name = list(s)
j = 0
last = ' '
last_count = 0
while j<len(name):
key = name[j]
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if count != 1 and key!='*':
if count>last_count:
last = key
last_count = count
j+=1
print(last, last_count)
9。元音出現頻率 (a,e,i,o,u)
vowels = ['a','e','i','o','u']
last = ' '
last_count = 0
s = 'guruprasanna'
name = list(s)
j = 0
while j<len(name):
key = name[j]
if key in vowels:
count = 1
i = j+1
if key != '*':
while i<len(name):
if key == name[i]:
name[i] = '*'
count+=1
i+=1
if key!='*':
print(key, count)
j+=1
輸出：
u 2 a 3
以上是Python day-Dictionary，使用嵌套循環的字元頻率的詳細內容。更多資訊請關注PHP中文網其他相關文章！
