Jupyter Notebookを使ってPythonの基本文法をまとめた

Pythonの基本文法

3+3

6

3-2
4*5
6/2
7%2 #最後に実行された行の返り値のみ

1

type(1)

int

type(1.0)

float

type(3.14)

float

type('string')

str

'hello'[2]

'l'

'hello'[1:3]

'el'

'hello{}'.format('world')

'helloworld'

print('{one}{two}'.format(one='hello', two='world'))

helloworld

List

list_out = [1,2,'three']
list_out

[1, 2, 'three']

list_in = ['one', 'two', 3] list_out.append(list_in) print(list_out)

list_out[1]

2

list_out[3][1]

'two'

list_out = [1,2,'three']

Dictionary

dict = {'key1':'value1', 'key2':2}

dict['key1']

'value1'

dict = {'key1':[1,2,'value1']}

dict['key1'][2]

'value1'

dict = {'key_out':{'key_in':'value_in'}}

dict['key_out']

{'key_in': 'value_in'}

dict = {'key1':'value2', 'key2':2}
dict['key3'] = 'new_value'

dict

{'key1': 'value2', 'key2': 2, 'key3': 'new_value'}

Tuples

list1 = [1,2,3,4,5]
tuple1 = (1,2,3,4,5,6)

list1

[1, 2, 3, 4, 5]

tuple1

(1, 2, 3, 4, 5, 6)

list1[1] = 10 #listは変更可

list1

[1, 10, 3, 4, 5]

tuple1[1] = 10 #tupleは変更不可

---------------------------------------------------------------------------

TypeError                                 Traceback (most recent call last)

<ipython-input-38-df5023792f06> in <module>
----> 1 tuple1[1] = 10 #tupleは変更不可


TypeError: 'tuple' object does not support item assignment

関数

result_list=[] #頻出
for i in range(0,4):
    result_list.append(i*10)

result_list

[0, 10, 20, 30]

[i*10 for i in range(0,4)]

[0, 10, 20, 30]

i=0
while i<5:
    print('{} is less than 10'.format(i))
    i+=1

0 is less than 10
1 is less than 10
2 is less than 10
3 is less than 10
4 is less than 10

lambda関数

def function_name (param1, param2):
    print('Do something for {} and {}.format(param1, param2)')
    
    return 'param1' + 'and' + 'param2' 

param1 = 'something1'
param2 = 'something2'
output = function_name(param1, param2)

Do something for {} and {}.format(param1, param2)

def get_filename (path):
    return path.split('/')[-1]

get_filename('/home/school/pet/corona')

'corona'

lambda path: path.split('/')[-1]

<function __main__.<lambda>(path)>

x = lambda path: path.split('/')[-1]

x('/home/school/pet/corona')

'corona'