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Python Development Ide:pycharm,eclipse

#下载专业版而且不要汉化33

An. operator

1. Arithmetic operator: +-*/*%//

2. Member operator: in not in result is Boolean type

Name='Li Jongdan'#if ' Li Dan ', the error is output#' Li Jongdan ' Dan is a substring, a subsequence#Ctrl + after selection? For all commentsif "is" inchName:Print("OK")Else:    Print("Error")if "Dan"   not inchName:Print("OK")Else:    Print("Error")

3. Comparison operators: = = > < >= <=! = does not equal <> not equals not to negate

4. Logical operators: And OR

user="Alex"pwd="123"v=user==" Alex "  and pwd=="123"or and pwd=="  728684"print(v)

Add: priority is calculated in parentheses first
True before or after or whatever is true behind
False and no matter what is behind it is false

5. Assignment operator + = *=-=/=

Summarize:

The result in the operator is the value: arithmetic operation assignment; result is Boolean comparison operation logical operation member operation

Two. Basic data type CTRL + LEFT mouse button

1. All the functions of the digital int are placed in int

#Python3, all shaping numbers are shaped int#Python2, small numbers are shaped int, over range is long#Shaping int#string str#Lists List# Tuple tuples#Dictionary dict#boolean bool#int function 1 conversion Converts a string to a numberA="123"b=Int (a) b=b+100Print(b)#int function 2 Converts the other binary to 10 binarynum="0011"v=int (num,base=2)Print(v)#the function of int 3 bit_length The binary of the current number, represented by at least n bits#1 1#2 Ten#3#4Age=4R=age.bit_length ()Print(r)

2. String str

test="Alex"#function 1 Initial capital letterv=test.capitalize ()Print(v)#Convert all letters to lowercase, casefold more powerful, many unknown correspondence can be converted to lowercasev1=Test.casefold ()Print(v1) V2=Test.lower ()Print(v2)#Set the width and center the content#After the parameter does not write the default is blank, support to fill a characterV3=test.center (20,"*")Print(v3)#Count occurrences, support characters and sub-sequences, and two parameters behind indicate start and end positions#start position is starting from 0V4=test.count ("e", 2,3)Print(v4)#indicates what end or what to start with, can be a character and a stringV5=test.endswith ("a")Print(V5) V6=test.startswith ("a")Print(V6)#find the first satisfying condition and get the position interval for the character or subsequence to >=0 and <1#not found, then-1V7=test.find ("e", 0,1)Print(V7)#formatting: Replacing the contents inside the brackets#test= ' I am {name},age={a} '#print (test)#V8=test.format (name= ' Alex ', a=19)#print (V8)test='I am {0},age {1}'Print(test) V8=test.format ('Li Jongdan', 19)Print(V8)#formatting, different ways of passing valuestest='I am {name},age={a}'V9=test.format_map ({'name':'Alex','a': 19})Print(V9)#Index is similar to find in the location of the index. #The difference is that find can not find the -1,index can not find a direct error#V10=test.index ("E", 0,1)#Print (v10)#determines whether a string consists only of numbers or letterstest="dsidhsi890+"v=Test.isalnum ()Print(v)

Complements the use of the tabulation function

# the tab \ t uses, along with the preceding string, a total of n lengths, enough to be padded with blanks test="useranme\temail\tpassword\nlzd\[email protected]\ T123\nlzd\[email protected]\t123\nlzd\[email protected]\t123\n"v=test.expandtabs  Print(v)

3. List of lists

4. Tuple tuples

5. Dictionary Dict

6. Boolean bool

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