Python max(). :
from random import random
#
L=[0]*20
L=list(map(lambda x: random(),L))
print (L)
#
Lmax=L[0]
for i in range(1,len(L)):
if L[i]>Lmax:
Lmax=L[i]
print ('Lmax=',Lmax)
Python sort. .
#
# 1 L L1
L1=[L.pop()]
while len(L)>0:
x=L.pop() # L
for i in range(0,len(L1)): #
if L1[i]>x: #
L1.insert(i,x) # L1
Break
else:
L1=L1+[x] # - .
print ('L1=',L1)
/
:
# 1,2,3...99
L1=list(range(1,100))
#
L2=[x for x in L1 if not (30<x<70)]
, . my_remove, , , :
def my_remove(L,f):
""" L , f"""
i=0
while i<len(L):
if f(L[i]):
L.pop(i)
else:
i+=1
# 1,2,3...99
L1=list(range(1,100))
#, ,
def f1(x):
return 30<x<70
# , f1
my_remove(L1,f1)
print (L1)
my_remove , , , . , my_remove .
(, key) (). : {1:1, 2:2}
, . , ,
atomic_mass = {'H': 1.,'C': 12., 'S': 32.}
atomic_mass['O'] = 16
print (atomic_mass['O'] + 2*atomic_mass['H'])
, :
Balance={"q_e":.4607056475,"q_r":.1330927426e-1,"q_w":.7739854878e-1,"q_":.3111795140,"q_":.5584776238e-1,"q_":.8155925314e-1,"q_":.1373464876}
print (list(map(lambda x:Balance[x],["q_e","q_r"])))
|
|
|
:
| x = d[k] | key |
| d[k] = x | key |
| del d[k] | key |
| k in d | key |
| len(d) |
'O' :
del atomic_mass['O']
print (atomic_mass)
:
{'C': 12, 'S': 32, 'H': 1.0}
, , . , , , :
d = { }
d[1,2,3] = foo
d[1,0,3] = bar
dict.clear() - .
dict.copy() - .
classmethod dict.fromkeys(seq[, value]) - seq value ( None).
dict.get(key[, default]) - , , , default ( None).
dict.items() - (, ).
dict.keys() - .
dict.pop(key[, default]) - . , default ( ).
dict.popitem() - (, ). , KeyError. , .
dict.setdefault(key[, default]) - , , , default ( None).
dict.update([other]) - , (, ) other. . None ( !).
dict.values() - .
csv DictWritter, . :
import csv
toCSV = [{'name':'bob','age':25,'weight':200},
{'name':'jim','age':31,'weight':180}]
keys = toCSV[0].keys()
with open('people.csv', 'wb') as output_file:
dict_writer = csv.DictWriter(output_file, keys)
dict_writer.writeheader()
dict_writer.writerows(toCSV)
set frozenset :
| s | t | s t |
| s & t | s t |
| s t | s t |
| s ^ t | s t |
| len(s) | |
| max(s) | |
| min(s) |
