Detailed features characters taken involving python explain:
= STR '0123456789'
Print ( "STR [0: 3]:" + STR [0: 3]) # 0 to 3, the forward taken string (excluding 3) i.e. 012
Print ( "STR [:]:" + str [:]) # positive output all strings i.e. 0123456789
Print ( "STR [. 6:]:" STR + [. 6:]) # 5 from the forward output string (excluding 5) end i.e. ~ 6789
Print ( "str [: - 3]: " + str [: - 3]) # ~ positive output from the start of the countdown of three characters (excluding third) i.e. 0123456
Print ( "STR [2]:" + STR [2]) # i.e., output of the third character 2
Print ( "STR [: -. 1]:" STR + [: -. 1]) output from the forward start ~ # penultimate first character (which does not contain a ) i.e. 012345678
Print ( "STR [-1]:" + STR [-1]) # i.e., output of the last character. 9
Print ( "STR [-3: -1]:" STR + [-3: -1]) # reverse order output from the penultimate penultimate 3 to 1 (exclusive) i.e. 78
Print ( "STR [-3:]:" STR + [-3:]) # reverse order output from the third to the last countdown i.e. 789
Print ( " str [:: - 1]: " + str [:: - 1]) # reverse order output,All i.e. continuous output string 9876543210 All i.e. continuous output string 9876543210
Print ( "STR [:: - 2]:" + STR [:: - 2]) # reverse order output from the last start, outputs a string of two every 97,531
Print ( "STR [::. 1]:" + STR [::. 1]) # n-order output, i.e. continuous output all strings 0123456789
print ( "str [:: 2] :" + str [:: 2]) # n-order output, starting from the first one, every two outputs a string that is 02468
Print ( "STR [: - 2:. 4 ]: "+ str [: - 2: 4]) # n outputted from the first sequence start, a character output every four i.e. 04
Print (" STR [. 1: -2:. 4]: "STR + [. 1 : -2: 4]) # n outputted from the second sequence start, a character output every four i.e. 04
Simple law Summary: There are two general forms of string interception
[:] This form is where to intercept where to find it if it is negative from the back
[::] The first such form: string representing processing second: intervals taken positive number represents positive output, a negative output representative of reverse
Output is as follows: STR [0:. 3]: 012 STR [:]: 0123456789 STR [. 6:]: 6789 STR [: -. 3]: 0123456 STR [2]: 2 STR [: -. 1]: 012345678 STR [- . 1]:. 9 STR [-3: -1]: 78 STR [-3:]: 789 STR [:: -. 1]: 9876543210 STR [:: - 2]: 97531 STR [::. 1]: 0123456789 STR [ 2 ::]: 02468 STR [: - 2:. 4]: 04 STR [. 1: -2:. 4]: 15
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reference link: https: //blog.csdn.net/qq_21840201/article/details/85084621