Looping statements in the 20:python

20.1 whileStatement

Problem Description:

please 5!.

Tips:

ask for factorial of 5, i.e. 5*4*3*2*1

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I always feel not intuitive, I think the final print is the shape of: 5 ! = 5*4*3*2*1 =

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20.1.1 Printhow to get rid of line wrapping

How do I get rid of line breaks?

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remove the newline, but the middle clip has a space, how to remove the space?

20.1.2 PrintHow to remove spaces

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Personal Exercise: How to implement a number from the keyboard input (need to judge more than 0 ) to calculate the factorial of it.

20.2 forStatement

Problem Description:

write the program to put the string ' I love python ' print out as a single character.

The effect is as follows:

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where the I of line 4 represents the loop variable,for,in, followed by the colon are fixed format, and ' I love Python ' is a string.

line 5, print I, a comma means no wrapping, and the loop variable i automatically accumulates.

Personal Exercise: How to achieve the delay effect

20.2.1 forLooping Format

pythonfor loops can traverse any sequence of items, such as a list or a string.

Grammar:

for The syntax format for the loop is as follows:

for I in sequence Span style= "font-size:13px;font-family: ' Courier New '; color: #666600; border:none 1px;padding:0;" >:

Statements (s)

Flow chart:

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20.3 Rangefunction

The Range function is often used in conjunction with a looping statement.

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Problem Description:

we want to realize 1+2+3+4+5+ ... +100 and, how is Python code implemented?

Tips:

we know 1+2+3+4+5+ ... +100=5050

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Range ( n,m ) function does not include the right boundary. So, there is no addition .

4950+100=5050.

Section 4 Line, s=0 , if not, the compilation will error, indicating 6 Line s not defined. "Variables must be defined before they are used"

individual try to remove line 4

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20.3.1 Rangefunction Considerations

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20.4 Enumeratefunction

The for statement implements two loop variables

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The list will be explained in more detail later.

Personal Practice: Print 1-9 Triangular Array :

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Looping statements in the 20:python