Python基礎(1)保留字數據類型運算符format

1.保留字與標識符

import keyword
print(keyword.kwlist)
print(len(keyword.kwlist))

輸出:

['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']
35

2.基本數據類型

整型
浮點型
字符串
布爾類型(代表真或假的數據類型,值只有True或False)

3.運算符

1.賦值運算符 =
2.算術運算符 (+,-,,/, %,//,**)
3.複合運算符 (+=,-=,
=,/=,%=,//=,**=)
4.位運算符 (&按位與,|按位或,^按位異或,~按位取反,<<左移 , >>右移)
5.比較運算符 ( >, <, >=, <=, !=, <>(也是不等於) )
6.邏輯運算符 ( and(並且), or(或者), not(不是), is(是) )
7.成員運算符 in/not in 判斷給定的元素是否在列表,字典或元組,集合
8.身份運算符 is/is not 判斷給定的元素是否是某一個引用的數據

4.輸出print與format

(1)print

str = 'hello' 
length = len(str) 
print('字符串%s的長度爲%d'% (str, length))

輸出:

字符串hello的長度爲5

拓展:Python中%(常用的) %s字符串 %e指數 %f浮點數 %%字符%

(2)format

1.字段名字爲整數,表示參數的位置

print("my name is {0} and my age is {1} years old".format('sunlin', '100'))

輸出:

my name is sunlin and my age is 100 years old

2.字段名字爲參數的名字

print("my name is {mingzi} and my age is {nianling} years old".format(mingzi = 'sunlin', nianling = '100'))

輸出:

my name is sunlin and my age is 100 years old

3.列表的取值

print("my name is {0[0]} and my age is {0[1]} years old".format(['sunlin', 100]))
print("my name is {[1]} and my age is {[2]}".format(['sunlin', 'dagou', 'ergou'], [21, 34, 47]))

輸出:

my name is sunlin and my age is 100 years old my name is dagou and my
age is 47

4.字典的取值

infor = {'ming_zi': 'sunlin', 'nian_ling': '24'}
print("my name is {ming_zi} and my age is {nian_ling}".format(**infor))

輸出:

my name is sunlin and my age is 24

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