print ( ) #display. Enclose the character string in "" or "". The numbers remain the same.
print ( a + b ) #Character strings can be combined as shown on the left.
print (letter+ str (Numbers) ) #Pay attention to the type when joining.
print （ a , b , c ） #The result of this execution is a b c.
print ( a , b , c , sep = " " ) #abc is the result.
#usually,When separated by, a half-width space is inserted by default.
#Also,When separating with, there is no problem even if the molds are mixed separately.
#The delimiter can be changed from half-width by the character string specified by sep.
new line= /n
tab= /t
print("""/
...
...
... """) # /It is also possible to write from the first line without entering.
len(variable) # variableの文字数をカウントして出力することが可能。
#When specifying a character string in the variable()Line breaks are also free if you come out.
#However, the parts other than "" are not reflected, and line breaks are also included.\Only when indicated by n.
#For text*It is also possible to repeat by setting 3 etc.
#Syntax Error is an error that the code is written or the syntax is incorrect.
#The following error is sometimes called Exception compared to Syntax Error.
#Name Error is an error that occurs when an undefined variable name is used.
#Identification Error is an error that has unnecessary white space or does not have necessary white space.
#Type Error is an error that uses an object of an inappropriate type in a function or the like.
#What is a type str(String)・ Int (integer) ・ float (floating point number).
#The quotient becomes a float type. Also, although this rarely appears, there is also a complex number complex.
#Almost no more, but bool (True)/False) ・ NonType (None) also exists.
+ #addition
- #subtraction
* #multiplication
/ #Division (penetrate to the decimal point)
// #Division (integer with decimal point rounded down)
% #Too much division
** #Exponentiation
a = b #Substitute b for a. It will be overwritten each time it is assigned.
a += 2 #Increase the value of a by 2. a=a+A syntax that has the same meaning as 2.
a -= 2 #Decrease the value of a by 2. a=a-A syntax that has the same meaning as 2.
a *= 2 #Multiply the value of a by 2. a=a*A syntax that has the same meaning as 2.
a /= 2 #Divide the value of a by 2. a=a/A syntax that has the same meaning as 2.
a == b #a and b are equal (if ,,,
a != b #a and b are not equal (if ,,,
a > b #a is greater than b (if ...
a < b #b is greater than a (if ...
a >= b #If a is greater than or equal to b (in the case of, ...
a <= b #b is greater than or equal to a (in the case of, ...
and #Multiplying conditions (logical product)
or #One of the conditions (logical sum)
not #Show denial
if conditional expression:
processing........
elif conditional expression:
processing........
elif conditional expression:
processing........
else:
processing........
#If you use if a in dictionary, check if the dictionary contains a. The dictionary can be a list.
#On the contrary, if you want to do it if it is not included, you can do it with not in.
#Nesting control structures such as if, for, and While is called nesting.
numbers = [ aaa , bbb , ccc , ddd … ] #index
x = numbers[0] # aaa
print(numbers[1:3]) # bbb,ccc
print(numbers[:2]) # aaa,bbb
print(numbers[2:]) # ccc,ddd
#List name[Reference point]Can be specified with.
#Regarding the reference points, from 0 in order from the left, from the right-Specify from 1.
#list[ ]There is no concept of type. There is a type( )in the case of.
#Index from 0 in ascending order from left, index from right-It starts from 1 in descending order.
print(numbers[Position 1:Position 2:2]) # aaa,ccc
#Position 1 indicates the start position, position 2 indicates the end position, and 2 indicates the step (every 2) count.
x = aaa , bbb , ccc , ddd … #When there is such a list
numbers = x.split(",") #This is an index.","Is the delimiter.
#Also, if it is a list, use a dictionary when you forget where and what number you put.
#By doing this, it is possible to pull out by name, not by index position.
with open("xxx/xxx.csv",encoding="utf-8") as f:
f.readlines() #It is possible to list by line
numbers = {}
numbers["name"] = aaa
numbers["Street address"] = bbb
numbers["sex"] = ccc
numbers["age"] = ddd
numbers[key] = value #When officially shown, it looks like this.
#At this time, the place that normally corresponds to the index is called Key, and the value is called Value.
numbers = {"name":"aaa","Street address":"bbb","sex":"ccc","age":"ddd"}
#Key like this:It is also possible to type in the dictionary as it is by writing it in Value.
del numbers["name"] #By doing this, the corresponding item can be deleted.
numbers.pop("name") #This is the same process as above.
numbers.get("a","b") #If there is an item called a, its Value, if not, b.
#If b is not set in get or blank in return, None will be the return value.
numbers.keys() #Extract the key in the form of a list. dict_keys()Comes to my head.
list(numbers.keys()) #If you make this shape. You can get rid of your head and list it completely.
numbers.values() #Extract values in the form of a list. dict_values()Comes to my head.
list(numbers.values()) #If you make this shape. You can get rid of your head and list it completely.
numbers.items() #Extract items in the form of a list. dict_items()Comes to my head.
list(numbers.items()) #If you make this shape. You can get rid of your head and list it completely.
x.append ( "Additional elements" ) #Add the elements in parentheses to the end of the list.
x.insert (insert position, "Additional elements" ） # Additional elementsを指定の位置に挿入。
x.pop (position) #Delete the value at the specified position. If there is no entry, the last value is deleted.
for x in list: #Assign each element of the list to x for processing.
processing........
for key in dictionary name: #Substitute the dictionary keys in order. It can be the key x.
processing........
print(key) #Show Key
print(Dictionary name[key]) #Show Value
for key,value in dictionary name.items() #key and value are arbitrary strings.
processing........
print(key) #Show Key
print(value) #Show Value
pass #Used when you want to finish without executing anything, but you get a syntax error if you do not write anything.
break #If there is a condition that you want to stop iterative processing~~ :End with break.
continue #It can be used when you want to skip the iterative process only that time.
f = open ( "file name" , encoding = "utf-8" )
x = f.read() #read and name it x
f.close() #close
#In the above method, it is easy to forget to close, and in most cases it opens in the following form and is automatically closed.
with open ( "file name" , "How to call" , encoding = "utf-8" ) as f
# r :Read-only. (Cannot be written.) Can be omitted.
# w :Call when writing. If the file does not exist, create a new one.
# x :Create and write the file only if the file does not exist.
# a :Write at the end. If the file does not exist, create a new one.
with open ( "file name" , "How to call" , encoding = "utf-8" ) as f
for x in f: #Extract line by line from f
print(x) #On each line\n is print\Since n is added, there is a space between lines.
x.strip() #Omit the blank elements that exist at both ends.
x.rstrip() #Omit the blank element that exists at the right end.
x.lstrip() #Omit the blank element that exists at the left end.
#Also, when calling it, it is called with the basic character string str, so if you want to calculate numbers, int conversion is required.
x.split(",") # ,Split the text with.
x.join(",".join(list)) # ,を区切り文字にlistをテキストに結合する。
x.replace("Original string","Replacement string","Number of replacements") # Number of replacementsは制限なし。省略可。]
"text%dtext" %variable#Use the value of a variable. (Number string)
"text%stext" %variable#Use the value of a variable. (Character string)
print("{1},{2}!!".format("Say","Hello")) #Use the format element with index specification.
{:d} #Display the specified number as an integer system
{:5d} #Displayed in integer system, then right-justified with 5 digits
{:05d} #Same as above, but the remaining digits are filled with 0 and displayed
{:,d} #Show comma-separated integer values every 3 digits
{:f} #Display the specified number up to 6 decimal places
{:.3f} #Display the specified number up to 3 decimal places
"text{name}text".format( name = "xxx" ) #You can also insert it later.
#format is nothing{}If you don't put it inside, you will feel like you are going to apply it in order from the front.
x.startswith("Yamada") # Yamadaから始まる
x[:2] == "Yamada" # 最初の２文字がYamada
x.find("Yamada") = = 0 # Yamadaを探したら先頭にあった
import random #Import random module
#Used for numeric assignment and new list generation
random.randint(Number of starts,Number of ends) #Any integer value from start to end
random.uniform(Number of starts,Number of ends) #Any floating point value from start to end
random.choice(list) # listの中のどれかをピックアップしてくる
random.sample(list,Number of indexes) # シャッフルし新規list生成。
#Make changes to the randomly generated original list itself
random.shuffle([list]) # 上記と異なり元listそれ自体をシャッフル。
from datetime import datetime #Up to seconds
from datetime import date #Until the day
from datetime import timedelta #Call when also performing difference calculation
print(datetime.now())
datetime.now() # 2019-01-10 13:16:48.904193 -now
datetime.year # 2019 - %Y (corresponding format symbol)
datetime.month # 01 - %m (corresponding format symbol)
datetime.day # 10 - %d (corresponding format symbol)
datetime.hour # 13 - %H (corresponding format symbol)
datetime.minute # 16 - %M (corresponding format symbol)
datetime.second # 48 - %S (corresponding format symbol)
datetime.date() # 2019-01-10
datetime.time() # 13:16:48.904193
datetime.datetime() # 2019-01-10 13:16:48.904193
date.today() # 2019-01-10 -now
#Get it as a time element if you add parentheses at the end, or as a character string if you do not add parentheses.
timedelta(days=3)
#Show the difference. before+Or-By adding, you can add or subtract the intervals in parentheses.
# ()If there are only numbers inside, days=It will be calculated in, but it is kind to write it every time.
f'{formula= :Format}' #You can make a formula with this. The format is specified by the format characters.
f'{formula:Format}' #Conversion from date and time to string
datetime.strptime(formula,"書formula") #Conversion from string to date and time
x = datetime(Year,Month,Day,Time,Minutes,Seconds) # これで任意のDay付定義が可能。
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