Grade: B+

With a Mike Leigh film, you never quite know what you’re going to get (and, given his technique of fashioning the script from his actors’ improvisations, neither does he); it can be as stark as “Naked” or as lovely as “Topsy-Turvy.” This time around, he and his cast give us one of his most charming pieces, a character study that’s as frothy and crowd-pleasing as “Naked” was painful and pessimistic. That’s not to say that “Happy-Go-Lucky” doesn’t have its dark moments. Overall, though, it’s a wonderfully life-affirming tale of a woman who always looks on the bright side of things and tries to make matters better when she runs into unhappiness.

She’s Poppy (Sally Hawkins), a grammar-school teacher deeply attached to her young charges and supportive of her roommate Zoe (Alexis Zegerman), her university-student sister (Kate O’Flynn), and her other friends. She’s sort of a Pollyanna figure, spreading sunshine wherever she goes and refusing to be deterred by any setbacks—when her bike is stolen, she simply signs up for driving lessons with an angry, embittered instructor named Scott (Eddie Marsan), whose spirits she tries to raise—but as played by Hawkins, she doesn’t become an annoyingly bubbly figure but rather a thoroughly likable (if still bubbly) one.

There’s a sort of Candide-like quality to Poppy’s episodic adventures. Some are deliciously off-the-wall, like her flamenco lessons with a hard-nosed Spanish instructor (Karina Fernandez) who challenges her British students to show some heat and attitude. But most are a mixture of the sweet and sour—like her concern for a troubled student that leads to a romance with dedicated social worker Tim (Samuel Roukin), or her relationship with Scott, who proves to be a simmering time bomb of resentment, or an encounter with a babbling street person (Stanley Townsend), or a visit to her pregnant younger sister (Caroline Martin) and her milquetoast husband (Oliver Maltman) where signs of family tension threaten even Poppy’s inveterately upbeat outlook.

“Happy-Go-Lucky” can certainly be criticized for meandering as much as its heroine does. The flamenco sequences are delightful, but wholly digressive; and so is another episode, in which Poppy’s trampoline exertions are followed by a visit to a physical therapist. But the whole of the picture is basically a series of cadenzas, which could be a problem were they not almost uniformly engaging. And it has the perfect anchor in Hawkins, who somehow manages to keep Poppy from descending into either comic caricature or teary treacle. The rest of the cast deliver memorable turns—helped no doubt by their intense involvement in the creative process. But among them Fernandez, and even more Marsan, stand out, she for a delectable cameo and he for a lengthier depiction of a man who’s alternately hilariously absurd and genuinely scary.

On the technical side, cinematographer Dick Pope uses the anamorphic format to excellent effect, not only in the split-screen credits sequence but throughout, and the production crew has given the picture a real sense of space and a lived-in feel. Gary Yershon’s jaunty score mirrors Poppy’s own sprightliness while managing not to overdo.

The result is an aptly-titled movie: it will make you feel both happy and lucky to have gone to see it.